How TO: CEL/MIL Eliminator!

[96superneon]

hmm im suprised at how many people have to use the non fouler.... i used cap and resistor method and it works flawlessly!! i have to admit though soldering is way harder than i thought it would be. oh and when i did it i used the pic on page 12 which i think is setup a bit different then the diagram on page 1. the diagram shows connector----capacitor----resistor----sensor
the picture shows connector----resistor----capacitor----sensor. good luck!

 

[MSPDriver]

Ok I've tried everything, I keep getting check engine lights. I've used those spark plug spacer things. I put the capacitor and resistor on. I know I bought the right ones. It worked for a few months but now it keeps throwing the code. I looked at it again and it looks like all my wiring is fine. I don't know what to do....

 

[Protege__Owner]

Hello fellow members,
Hopefully someone on this thread could help me out. I've already posted once on the other thread referring to the non-fouler fix. That was about 2 months ago and no one replied. Hope someone here could share some knowledge.
I drive a 2001 Protege ES 2.0L. Have about 97k miles on it now. I know my primary cat is going bad because I'm getting code P0421 on and off for the last few months.
I was planning to put in the non-fouler fix, but just recently started getting a new code P0037. I believe that is my second o2 sensor going bad? Or do you think it's a false reading due to the bad cat?
Will the non-fouler work on a bad cat or only for headers? (I'm planning to leave the stock primary cat in and just do the non-fouler)
Now will a non-fouler trick work if the o2 sensor was defective? Thanks for any input!

 

[BinoMP5]

did both... still throwin CELs... we've become friends actually... it visits once in a while... especially during highway drives... but goes away with in-town traffic.... anyone else experiencing this?

i think, this is just me, that you just have a bad cat... and since the so-called CEL/MIL eliminator hasn't been 100% effective... it's really up to you if you want to do it... the people with a header on "need" it to fool the 02 sensor... i was throwing the same exact code(p0037)... the guy said that there's another code when the actual O2 sensor is messed up or even dirty... but with you having a stock exhaust, that shouldnt be the case... try cleaning it if you want...

but if you really want to get rid of CELs completely... go StandAlone and CELs will be a thing of the past

 

[cougar10agREDUX]

Hello fellow members,
Hopefully someone on this thread could help me out. I've already posted once on the other thread referring to the non-fouler fix. That was about 2 months ago and no one replied. Hope someone here could share some knowledge.
I drive a 2001 Protege ES 2.0L. Have about 97k miles on it now. I know my primary cat is going bad because I'm getting code P0421 on and off for the last few months.
I was planning to put in the non-fouler fix, but just recently started getting a new code P0037. I believe that is my second o2 sensor going bad? Or do you think it's a false reading due to the bad cat?
Will the non-fouler work on a bad cat or only for headers? (I'm planning to leave the stock primary cat in and just do the non-fouler)
Now will a non-fouler trick work if the o2 sensor was defective? Thanks for any input!

DTC P0421 Warm-up catalyst system efficiency below threshold
DETECTION
CONDITION
PCM compares the number of HO2S (front) and HO2S (rear) inversions for a predetermined time. PCM
monitors the number of inversions the rear side performs while the front side inverts for a specified number
of times when the following monitoring conditions are met. PCM detects the inversion ratio. If inversion
ratio is below threshold, PCM determines that catalyst system has deteriorated.
MONITORING CONDITIONS
Engine speed is 1,5003,000 rpm.
Calculated load is 1548%(*1).
Vehicle speed is 28120 km/h {17.374.5 mph}.
*1: Maximum calculated load value varies depending on engine speed.
Diagnostic support note
This is an intermittent monitor. (CATALYST)
MIL illuminates if PCM detects the above malfunction conditions in two consecutive drive cycles.
DIAGNOSTIC MONITORING TEST RESULTS is available.
PENDING CODE is stored if PCM detects the above malfunction condition during first drive cycle.
FREEZE FRAME DATA is available.
DTC is stored in PCM memory.


DTC P0037 HO2S heater (rear) circuit low
DETECTION
CONDITION
PCM monitors HO2S heater (rear) control signal at PCM terminal 93. If PCM turns HO2S heater (rear) off
but voltage at terminal 93 still remains low, PCM determines that HO2S heater (rear) circuit has
malfunction.
Diagnostic support note
This is an intermittent monitor (O2 sensor heater).
MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles.
PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
FREEZE FRAME DATA is available.
DTC is stored in PCM memory.
POSSIBLE
CAUSE
HO2S (rear) malfunction
Open circuit between ignition switch terminal C and HO2S (rear) terminal C
Open circuit between HO2S (rear) terminal D and PCM terminal 93
Short to ground circuit between HO2S (rear) terminal D and PCM terminal 93
Poor connection at HO2S (rear) or PCM connector
PCM malfunction



the non-fouler trick would work for the P0421 if the O2 sensor isn't that bad, but won't do anything for the heater circuit. since your also getting a P0037 (rear heater circuit) I'd say check your rear O2 wiring for shorts/grounds, if everything looks good i would replace the sensor.

97k miles, if your O2 sensors have never been replaced, good chance your rear is toast. People say the protege O2 sensors don't last too long. and if you can spare the change i would replace the front as well. If your primary (front) O2 sensor is bad your engine won't be getting the corret AFR and you can suffer power loss and bad fuel economy

 

[Steel]

Well I put in the OBX header a couple months back, and did the non fouler trick.. and now im getting a CEL. I'll have to rune to the 'zone to check what codes it is, but you guys think it would just be better to switch my 150k mile rear O2 sensor out for a generic if it's throwing codes?

 

[cougar10agREDUX]

Well I put in the OBX header a couple months back, and did the non fouler trick.. and now im getting a CEL. I'll have to rune to the 'zone to check what codes it is, but you guys think it would just be better to switch my 150k mile rear O2 sensor out for a generic if it's throwing codes?

if it has that many miles on it it's toast... but first clean the non-foulers to see if the MIL goes away.

 

[chwood]

Anyone know offhand what gauge wire these are?

 

[kamprotege00]

I just tried this and the CEL didn't turn off. I just reset it by taking off the neg. terminal. If it doesn't stay off where can I look up the non-fouler trick. Keep in mind the o2 sensor is stock from the factory so it might be bad, but it was working fine before I put the OBX header on so i'm thinking it is still alright.

 

[AzteCypher]

I don't have a blue wire on my O2 sensor. I have 2 whites, 1 grey, and 1 black. Anyone know which one to wire the resistor?

 

[cougar10agREDUX]

you all need to do the non fouler trick, it's the easiest and most successful way. i've had the same two non-foulers on for over 40,000miles, most of that with the turbo and running rich as s***, with no problems, i passed 1 NY state emissions test, and now 3 NC state emissions tests.

what you all have to remember is that if your O2 sensors are bad or on the way out when you install the OBX header or delete the cat these mods will not help. you will need to replace the sensors.

also stay away from generic O2 sensors. protege ECUs are very finicky. a stock car might be able to run them with no problems, i always stay OEM when it comes to sensors.

 

[BackRoadGTO]

I just did an Ebay header install and the non-fouler trick didn't work for me. Its pretty straight forward so I know I didn't mess anything up, it just didn't work for my car. I took out the O2 sensor and wired in the cap and resistors and it still threw the code. I took out the non-foulers, leaving just the rewired 02 sensor, and everything is working perfectly for over 1,000 miles! I used two 480k resistors in series b/c I heard some people having trouble with the 1M resistor.

 

[cougar10agREDUX]

you can't do both. its one or the other

 

[02ProtegeDX]

I have tried both ways and neither of them have worked for me.

 

[02ProtegeDX]

any suggestions?

 

[TomBodet]

Thread necro!

Just tried this resistor method on my CA emissions 99 Protege. Getting a constant reading of 44 according to the PID info coming back so sounds like I shorted it. Just to double check, the cap ties into the one wire (not interrupting it), the resistor goes inline in the other wire with the cap tied into that too on the side of the connector, not the O2 sensor?

I also had gotten stuff for the non fouler method, but the head on the sensor is bigger than 1/2". It don't fit in the first non fouler. Haven't put a caliper on it yet but it looks to be the same size as the threaded end of the non fouler so no way to make it fit.

I've gotta crawl under and probably re-do my soldering but looking for other suggestions as the month is half over and I'm due now for emissions. I've been skating by resetting the last few years but there's some sensors not coming online in time before my warmup cat code gets thrown so can't get inspected.

Edit:
Found my problem, resistor snapped loose. I re-soldered the mess in a more sane way so now after a quick 20 mile highway trip I'm reading from .34 to .56. I have no idea what's normal or what constitutes low to throw the original MIL (0421 I think). Right now the no activity MIL is still sitting there; I'm hoping it'll clear when I go in to work today.

Just to clarify with the non fouler problem. I've drilled out the first one with a 1/2" bit. The problem is the head of the O2 sensor is bigger than 1/2" so it bottoms out when I try putting it in. I only get about 1/3 of the sensor threads into the non fouler before it stops.

Suggestions still welcome.

ETA:
Even with the downstream reading from .3ish to .5ish it still threw a MIL for no activity again. Pulled the whole thing and soldered in replacement wires. Now reading .1 to .8 so it's roughly doubled the span of values being reported.

Still fighting with getting the cat, evap and egr to be ready before my warmup cat error.