So many codes, so much "what to do?". 5 CEL codes...

[Midnight_P5]

First things first:

I'm fairly new to this forum, and so far it has been very welcoming, and I've learned a bunch about Pro5's and Mazdas in general.

I bought my 2003 Protege5 (I think it's a 2003.5, as it has the spare tire subwoofer) almost 2 weeks ago. It's in pretty decent shape for my intended purpose of using it as a secondary car. It's got 158,4xx miles on it, so it's a little long in the tooth, but it seems to run well. Or at least I assume it's running well, I've never owned a Mazda before. For all I know, it could be running like poo.

The previous owner warned me of a couple codes the ECU was throwing (evident by the CEL).

Well, I just got back from Autozone, and this thing threw 5 codes. Guy at the counter said I was the winner for today, as I had the most codes.

Here's the list:

• P0037 - "O2 sensor heater circuit low - bank 1 sensor 2"
• P0421 - "Warm up catalyst system (RH) efficiency below threshold"
• P0300 - "Random cylinder misfire detected"
• P0442 - "EVAP control system leak detected - small leak"
• P0660 - "IMCC actuator circuit malfunction"

Luckily, these have solutions that I've found on the board here:

• To my understanding, these are the 4-wire, heated O2 sensors. Since the "heater circuit" is reading poorly, I'm going to assume the O2 sensor is bad. Since this is "sensor 2", I guess that means it's the downstream sensor? Am I correct in reading into this? Or is the P0421 code causing this as well?
• This code can be thrown because of the P0300. I'll fix that first. Cat is probably bad, but I'm not spending money on it.
• I need to change the coils, wires, and plugs. RockAuto for parts, me for labor. Done deal.
• Could this be the gas cap? That's what I'm going to change first. Hopefully, that'll work. Does anyone know what else could cause this code?
• From what I've come across, this is the EGR valve. It probably needs cleaned/replaced, but a bunch of the things I've read said this code can be set off by the P0300 code if it goes untreated.

I'm going to be placing my order in at RockAuto ASAP, so I can get this fixed this weekend.

If anyone could offer any advice or tips or any kind of help at all, it would be greatly appreciated.

How I felt at Autozone:

 

[31N007]

To my understanding, these are the 4-wire, heated O2 sensors. Since the "heater circuit" is reading poorly, I'm going to assume the O2 sensor is bad. Since this is "sensor 2", I guess that means it's the downstream sensor? Am I correct in reading into this? Or is the P0421 code causing this as well?

I will go with somewhat likely. Replace the sensor and see what happens from there. I wish I could point you in the direction of a good replacement, but I only know Rockauto, and the sensors are around $50 or so on there IIRC.

This code can be thrown because of the P0300. I'll fix that first. Cat is probably bad, but I'm not spending money on it.

P0300 is misfire due to a small number of things. Intake leak, bad coil pack, bad sparkplug, or something else. Replace the sparkplugs and if it comes back on humid days (you'll be able to feel the misfire quite well), look into replacing the coil packs. I had a P030(1,2,3,4) which denoted the cylinder number. Replaced both coil packs to be safe and (damn, I just jinxed myself) haven't had a major issue since.

P0442 - "EVAP control system leak detected - small leak"
P0660 - "IMCC actuator circuit malfunction"

I don't know these two, unfortunately. I had a really random one that I think might have pointed towards the gas cap, but I reset the code and it hasn't come back since. For P0660, see this thread: http://www.mazdas247.com/forum/showthread.php?123842039-Codes-P0660-amp-P1569 and have a look around. If you search "P0660 mazdas247" on the Google machine, it came up with this thread. Hopefully that'll help point you in the right direction there.

A bit of insight into the P0442, here's the list that the FSM says could be a cause of the code:

• Purge solenoid valve malfunction
• Canister drain cut valve (CDCV) malfunction
• Pressure control valve malfunction
• Loose or defective fuel filler cap
• Charcoal canister malfunction
• Catch tank malfunction
• Rollover valve malfunction
• Cracked fuel tank
• Fuel tank component parts poorly installed
• EVAP hose damaged or loose

There's a thread on here that has a link to the FSM and from there, you can more easily see what needs doing to rectify the issue.

It could be worse, you could be leaking fluids at an alarming rate. I'll take a CEL (of these varieties) over leaking like a sieve any day.

 

[The_big_dill]

• P0037 - "O2 sensor heater circuit low - bank 1 sensor 2" - Replace the sensor, these are wear items anyways, if its not the issue, you have done your car a favour.
  
• P0421 - "Warm up catalyst system (RH) efficiency below threshold" - If O2 sensor doesn't fix this (downstream), then your catalytic maybe no good. This could be a result of long periods of driving with a miss-fire.
• P0300 - "Random cylinder misfire detected" - This is either your coils or EGR. Personally have seen it be the EGR more often than coils. You can try cleaning it, but if the shaft inside is sticking, you need a new one.
• P0442 - "EVAP control system leak detected - small leak" - This could be something as simple as the gas cap, to something as serious as a hole in your gas tank or a cracked line somewhere... Unless this is limiting you from passing emissions, I wouldn't worry about it too much.
• P0660 - "IMCC actuator circuit malfunction" - This is almost ALWAYS the little solenoid with the white connector on top of your intake manifold. There are 2 of these solenoids on the intake on a little bracket. One connector is white (VICS) and one of the connectors is green (VTCS). If you want to confirm this, swap the 2 connectors between solenoids and see if you get a different code instead of P0660.

 

[Midnight_P5]

To my understanding, these are the 4-wire, heated O2 sensors. Since the "heater circuit" is reading poorly, I'm going to assume the O2 sensor is bad. Since this is "sensor 2", I guess that means it's the downstream sensor? Am I correct in reading into this? Or is the P0421 code causing this as well?

I will go with somewhat likely. Replace the sensor and see what happens from there. I wish I could point you in the direction of a good replacement, but I only know Rockauto, and the sensors are around $50 or so on there IIRC.

This code can be thrown because of the P0300. I'll fix that first. Cat is probably bad, but I'm not spending money on it.

P0300 is misfire due to a small number of things. Intake leak, bad coil pack, bad sparkplug, or something else. Replace the sparkplugs and if it comes back on humid days (you'll be able to feel the misfire quite well), look into replacing the coil packs. I had a P030(1,2,3,4) which denoted the cylinder number. Replaced both coil packs to be safe and (damn, I just jinxed myself) haven't had a major issue since.

P0442 - "EVAP control system leak detected - small leak"
P0660 - "IMCC actuator circuit malfunction"

I don't know these two, unfortunately. I had a really random one that I think might have pointed towards the gas cap, but I reset the code and it hasn't come back since. For P0660, see this thread: http://www.mazdas247.com/forum/showthread.php?123842039-Codes-P0660-amp-P1569 and have a look around. If you search "P0660 mazdas247" on the Google machine, it came up with this thread. Hopefully that'll help point you in the right direction there.

A bit of insight into the P0442, here's the list that the FSM says could be a cause of the code:

• Purge solenoid valve malfunction
• Canister drain cut valve (CDCV) malfunction
• Pressure control valve malfunction
• Loose or defective fuel filler cap
• Charcoal canister malfunction
• Catch tank malfunction
• Rollover valve malfunction
• Cracked fuel tank
• Fuel tank component parts poorly installed
• EVAP hose damaged or loose

There's a thread on here that has a link to the FSM and from there, you can more easily see what needs doing to rectify the issue.

It could be worse, you could be leaking fluids at an alarming rate. I'll take a CEL (of these varieties) over leaking like a sieve any day.

I'm definitely going to replace the O2 sensor ($28, RockAuto), and the coils/wires/plugs. That's just general maintenance that should be done. Especially since I have no accurate timeline for when they were last replaced. I also bought a new intake tube from RockAuto. I just think that's $25 well spent, to replace an intake tube that is 12 years old, with that many miles on it.

For the P0442, that's a lot of possible causes. I bought a new gas cap in my RA order, I'm hoping that fixes the issue. If not, I guess I'll start chasing it. I'll be needing to have the emissions test done at some point soon (part of the registration process in Maryland), so I will need to have it fixed.

Thanks for the help, I really appreciate it!

 

[Midnight_P5]

• P0037 - "O2 sensor heater circuit low - bank 1 sensor 2" - Replace the sensor, these are wear items anyways, if its not the issue, you have done your car a favour.
  
• P0421 - "Warm up catalyst system (RH) efficiency below threshold" - If O2 sensor doesn't fix this (downstream), then your catalytic maybe no good. This could be a result of long periods of driving with a miss-fire.
• P0300 - "Random cylinder misfire detected" - This is either your coils or EGR. Personally have seen it be the EGR more often than coils. You can try cleaning it, but if the shaft inside is sticking, you need a new one.
• P0442 - "EVAP control system leak detected - small leak" - This could be something as simple as the gas cap, to something as serious as a hole in your gas tank or a cracked line somewhere... Unless this is limiting you from passing emissions, I wouldn't worry about it too much.
• P0660 - "IMCC actuator circuit malfunction" - This is almost ALWAYS the little solenoid with the white connector on top of your intake manifold. There are 2 of these solenoids on the intake on a little bracket. One connector is white (VICS) and one of the connectors is green (VTCS). If you want to confirm this, swap the 2 connectors between solenoids and see if you get a different code instead of P0660.

I bought a new O2 sensor in my RockAuto order, that will definitely be one of the things I change this weekend.

I have the coils/wires/plugs ordered as well. I'll change those and check the EGR valve while I'm in there. If the EGR valve is bad, I'll order one.

I have to have this car run through emissions testing sometime soon, so I have to have this issue cleared. I bought a gas cap, and after I change it, I'm going to clear the code. If the code comes back, I'll start chasing the other possibilities.

Ok, I'll check the connectors, wires and solenoid. If they're ok, I'll swap the connectors and see if anything happens.

Thanks for your insight, I appreciate the help!

 

[The_big_dill]

I bought a new O2 sensor in my RockAuto order, that will definitely be one of the things I change this weekend.

I have the coils/wires/plugs ordered as well. I'll change those and check the EGR valve while I'm in there. If the EGR valve is bad, I'll order one.

I have to have this car run through emissions testing sometime soon, so I have to have this issue cleared. I bought a gas cap, and after I change it, I'm going to clear the code. If the code comes back, I'll start chasing the other possibilities.

Ok, I'll check the connectors, wires and solenoid. If they're ok, I'll swap the connectors and see if anything happens.

Thanks for your insight, I appreciate the help!

Its the solenoids that go bad, not the wiring. P0660 won't trigger an engine light, it only leaves a DTC and affects performance. Look up VICS for a better explanation on what the system does.

Furthermore, I don't know the laws in Maryland, but here in Toronto, we are allowed 1 system "Not ready" to pass emissions with our year of vehicle. So if we have an emissions problem, it will be the last to be "Ready". This allows us to reset the engine light and drive around until all but 1 of these monitors is ready and go pass emissions.

 

[P-Funk!]

If this helps.. MD does not require emissions test to register the car. You will have a vehicle condition inspection (brakes, lights, etc).
BUT you can 'expect' an emissions test 'soon' after registration

To pass the evap small leak CEL: Fill the tank. Clear the code. Drive 150 miles without ever letting the tank get lower than 4/5th full (gas it constantly)...

(The small evap test cycle is triggered when tank is below 3/4 full.)

 

[Midnight_P5]

If this helps.. MD does not require emissions test to register the car. You will have a vehicle condition inspection (brakes, lights, etc).
BUT you can 'expect' an emissions test 'soon' after registration

That's more along the lines of what I meant. I'm taking it for inspection next week. Emissions will be soon after that. I just need to pass emissions. If it fails once, I can fix it and try again. But if it fails twice, they could pull the registration of the vehicle. They more than likely won't do that, but they have the option to.

To pass the evap small leak CEL: Fill the tank. Clear the code. Drive 150 miles without ever letting the tank get lower than 4/5th full (gas it constantly)...

(The small evap test cycle is triggered when tank is below 3/4 full.)

That's a handy little trick to know

 

[damien381]

Just wanted to give a thumbs up to the folks on this thread. Just picked up a Protege5 with 185K on it with 0300 and 0421.
P0300: Coils, plugs and wires didn't fix the 0300 so I'm going to aim for the EGR valve and see what happens.

P0421: I know the very non mechanical guy that sold it to me, because of these codes drove this ten miles on a P0300. Should I look at replacing the precat as well or skip it? No emissions tests here in this state so its not a big thing.

The second question I have is if I need to swap the 02 sensors after 185K and never being swapped? I pulled data on this with torque/BT reader and the 02 sensor didn't do well when the engine was cold, and was thrashing high and low after the engine warmed up. I've attached pictures of the data below. Thoughts on that?

 

[MrGiggles]

If an 02 is functioning normally it will switch rather quickly from .1-.9 volts. Those readouts are nothing out of the ordinary, except the post cat 02 should switch much more slowly if the catalyst is working. Yours appears to not be, hence the P0421.

Do the non fouler mod. It worked perfect on my car, I've even read that people pass emissions with it. The precat isn't crucial to operation or emissions.

 

[damien381]

If an 02 is functioning normally it will switch rather quickly from .1-.9 volts. Those readouts are nothing out of the ordinary, except the post cat 02 should switch much more slowly if the catalyst is working. Yours appears to not be, hence the P0421.

Do the non fouler mod. It worked perfect on my car, I've even read that people pass emissions with it. The precat isn't crucial to operation or emissions.

The non fowler trick is in the plan. Going to return the precat I bought. I'm more concerned work the P0300. Going after the EGR valve. Going to see if I can clean it.

Sent from my SM-G900P using Tapatalk

 

[damien381]

After a long hiatus of the car sitting in the garage I got the EGR swapped out. DRASTICALLY improved the issue but i've driving it around a bit since then and I still have an occasional rough idle and P0300 code when I slow down to idle. the P0421 code is there as well, but I just haven't gotten around to the non-fouler modification yet. What else do I start looking at?

I've got running data from the OBDII (BT reader and torque) on the short term fuel trim, the O2 sensors and all kinds of stuff, but I just don't see anything that jumps out at me. Any suggestions? Vacuum lines?

 

[n2stox]

http://www.mazdas247.com/forum/show...random-misfire-cylinder-3-solved-after-a-year

seafoam into your brake booster....

 

[damien381]

And the error code is BACK!! grumble

Problem Description: 2002 Mazda Protege5 2.5L 180K
The issue is always seen when driving slowly after a period of driving, usually over 55mph. Car starts to miss on what feels like multiple cylinders. There is shaking of the vehicle when this happens
CEL (check engine light) comes on and usually starts blinking with a considerable Loss of power

Error codes:
P0300 - Misfire on multiple cylinders
P0421 - Catalytic converter issue <-installed the non fouler

Workarounds:
Pull plug wires and reseat. I see spark jump and then the issue goes away when I reseat. I've done this once so far
Pull over shut off the car, sit for 20 minutes and restart, light goes solid and power is back. This doesn't always work
Pull over shut off the car, and turn it right back on, light goes solid and power is back. This doesn't always work

What's been done so far on this issue:
Coil packs replaced before I bought the car contacts look new and they used grease
Mass Air Flow Sensor Replaced before I bought the car.
EGR valve Replaced by me a few hundred miles ago.
Spark plugs Installed today with copper OEM plugs.
Old plugs had elements that were worn to points but were still gapped close to .044 all of them looked good with light brown / ash look to them.
Seafoam pumped into vacuum lines.

Vacuum lines Not able to find a leak
fuel pressure Not tested yet
Injectors Not tested yet
compression Not tested yet
Main ground Not tested yet
Battery Two shops say this is bad (JAN09 install) I'm planning on a new one
Crank position sensor original
fuel pump (filter built in) original
02 Sensors original
Pre Catalytic converter original
Main Catalytic converter original

My thoughts:
Mass Air Flow pull it and clean it?
Clear flood mode What does this tell me?
OBD2 reader and Torque app Look at some PIDS?
Oscilloscope Hook this up and try to look at the injector pulse?

What would you try next?

 

[MrGiggles]

Your symptoms sound like a bad coil pack. They can be very intermittent, and some don't last very long. I would warranty them and see what that does for you.

Clear flood mode is activated when the accelerator is pressed to the floor during cranking. The PCM kills the injectors to clear the flood condition, although you rarely ever see a fuel injected engine flood.

Injector pulse can be checked with a lab scope or a noid light.. Although you rarely see them fail, let alone fail intermittently.

 

[moparmansfield]

I was having 2 codes pop up, the heated 02 circuit and random misfire. Found my battery terminals corroded pretty bad, and while I was at it I cleaned and re-set all my grounds. After I cleaned all that up the codes went away and haven't come back and it idles smoother. I know it sounds too simple to be true, but I'm pretty sure there was high resistance causing low voltage issues. Worth a shot

 

[pasadena_commut]

Definitely check all the grounds. Unbolt the ground wires, clean off any corrosion on the wire and wherever it is mounted, and bolt them back in place. The car runs on a computer and sensors and those are not going to be happy if the grounds are flaky. If the car tends to act up on rough roads that would be a pretty good indicator of a loose/bad electrical connection - somewhere. It might be worth it to work around under the hood and clean all the electrical connectors with contact cleaner. Note, do that when the car is cold and off. Unhook the battery to prevent any possible sparks. Electrical contact cleaners tend to be very flammable.