Check Engine Light On

[racerchick]

so, I took my car to a mechanic today and he says that a sensor in my cold air intake is the reason for my check engine light being on. i don't know if this is for real or not. do you think it could be my maf sensor? what do you think it is?

[boostdprotegelx]

did he pull a code?? tell us what the code is. how's the car driving??

[racerchick]

what do u mean by "a code"? the car drives perfectly.

[boostdprotegelx]

check engine code.. when the light is on, you put a code reader into the OBD port to find out why the car is throwing the CEL..

[racerchick]

ooh ok. thanks! i will have to ask about that.

[boostdprotegelx]

ok cool post up when you find out and we'll help you out!

[slavrenz]

Yeah, it's most likely your MAF sensor. But if you said the car is running okay (usually a bad MAF sensor will make it run bad), it could also be your IAT (intake air temp.) sensor.

[8.5MS3]

just be careful, i dont know much about proteges, but my ms3 didnt run that bad when the maf crapped out. CEL came on and when i started monitoring my afr's were in the 16's. the cel was from the lean condition.

[racerchick]

yeah it was air temp sensor. I got it fixed and picked it up on thursday. The engine light just came on again this morning. It's pretty frustrating, but I don't know what else it could be...

[boostdprotegelx]

if it wasn't actually fixed. take it back to the shop, they'll have to fix it.

also, as mentioned. if you get a code, maybe we can help better.

[slavrenz]

if it wasn't actually fixed. take it back to the shop, they'll have to fix it.

also, as mentioned. if you get a code, maybe we can help better.

+1. There's no reason the shop shouldn't give you the associated CEL code, and there's no reason why you should have to pay another cent for them to fix a problem that they misdiagnosed.

[racerchick]

Alright, I finally took my car back to the shop to have them diagnose the CEL problem. They gave me the code. It's P0424, which is related to my catalytic converter. It's alot of money for me to fix that right now, and my car is past 80,000 miles so my warrenty with the manufacturer is out...that's what I've been told. Have you guys had this problem?? My only concern is that the problem was "supposedly" diagnosed and repaired the first time, but it obivously wasn't the problem in the first place. So how do I know after the second time that this is really the problem now for the CEL? If you have any advice or sources that will help please let me know! Thanks so much!!

[el_Don]

I think it's either a bad O2 sensor or a bad catalytic converter.

[boostdprotegelx]

agreed. if it is the 02 sensor, i'd try to replace it yourself. it's really easy.. and same with the cat. but before i go wasting hundreds of dollars on a new cat, i'd just go to a muffler shop and have them weld in a new pipe/cat.

[slavrenz]

Alright, I finally took my car back to the shop to have them diagnose the CEL problem. They gave me the code. It's P0424, which is related to my catalytic converter. It's alot of money for me to fix that right now, and my car is past 80,000 miles so my warrenty with the manufacturer is out...that's what I've been told. Have you guys had this problem?? My only concern is that the problem was "supposedly" diagnosed and repaired the first time, but it obivously wasn't the problem in the first place. So how do I know after the second time that this is really the problem now for the CEL? If you have any advice or sources that will help please let me know! Thanks so much!!

Go to another shop. First of all, they should've told you that the code is P0421 - warmup catalyst efficiency below threshold. P0424 isn't a valid code on the Protege5s. That said, it seems as if this is a fairly common problem on higher mileage Protege5s, and 95 times out of 100, the problem is that the catalytic converter near the exhaust manifold has either worn out, or been "killed" by a misfire resulting from neglected spark plugs or bad ignition coils.

It's true that the cat is covered by federal law for 8 years or 80k miles, whichever occurs first. What has me concerned is that fact that your mechanic told you that the initial problem was an intake sensor. This tells me that he either doesn't know what he's doing, or there actually is a problem with one of your intake sensors that is somehow messing up your car, and perhaps contributed to your catalytic converter failure.

Whoever you take the car to, make sure that they figure out if something else caused your cat to fail, or if there's another CEL code. Also, how much are they charging you to repair it? If they are using an OEM cat from Mazda, I would let them know that Walker exhaust makes an aftermarket cat (Part No. 16220) that is about 1/2 the price. Many shops user Walker exhaust parts anyway, so this may be a way for you to save some money.

[slavrenz]

agreed. if it is the 02 sensor, i'd try to replace it yourself. it's really easy.. and same with the cat. but before i go wasting hundreds of dollars on a new cat, i'd just go to a muffler shop and have them weld in a new pipe/cat.

How many times have you heard of the P0421 code being caused by a bad O2 sensor? While I'll admit that it is a theoretical cause of the issue, every person that I've known with this problem has replaced the O2 sensor, only to have to dump money on a new cat anyways.

I say if the sensor wiring's not visibly damaged, 90% of the time it's gonna be the cat.

[racerchick]

Go to another shop. First of all, they should've told you that the code is P0421 - warmup catalyst efficiency below threshold. P0424 isn't a valid code on the Protege5s. That said, it seems as if this is a fairly common problem on higher mileage Protege5s, and 95 times out of 100, the problem is that the catalytic converter near the exhaust manifold has either worn out, or been "killed" by a misfire resulting from neglected spark plugs or bad ignition coils.

It's true that the cat is covered by federal law for 8 years or 80k miles, whichever occurs first. What has me concerned is that fact that your mechanic told you that the initial problem was an intake sensor. This tells me that he either doesn't know what he's doing, or there actually is a problem with one of your intake sensors that is somehow messing up your car, and perhaps contributed to your catalytic converter failure.

Whoever you take the car to, make sure that they figure out if something else caused your cat to fail, or if there's another CEL code. Also, how much are they charging you to repair it? If they are using an OEM cat from Mazda, I would let them know that Walker exhaust makes an aftermarket cat (Part No. 16220) that is about 1/2 the price. Many shops user Walker exhaust parts anyway, so this may be a way for you to save some money.

That makes a hell of alot more sense...my brothers got real pissed when I told them how much the shop was going to charge me for replacing the cat + labor. He told me $800 for the cat alone, and with labor would bring it out to about $1,100. FREAKIN ridiculous! If my brothers, and you guys, are right about getting it way cheaper then I'm better off finding another way. I don't have that kind of money anyway.

To be honest with you, I really didn't feel right about what that guy was telling me in the first place. Just because I'm a woman doesn't mean I'll pay anything because I don't know anything. Damnit I'm not THAT stupid! Well, anyways, thanks for the advice!! :)

[fishdonotbounce]

Commence required leg humping of lady member (humpleg)

Lol jk but glad that the members here were able to help you in making the right decision and not going along with that crackpot's assumptions. Good luck with the car!

[boostdprotegelx]

not sure what exhaust shop or shop you went with, but most shops have well over a 200% markup... i know this because i used to work at Merchants tire in westminster maryland..(which is a tire kingdom store)..

anyways..

your best bet is to go to advance auto, napa auto parts, auto zone...etc.. one of those kinds of places, and order the part. and put it on yourself. or have your brothers do it!:) good luck!

[widgit117]

(humpleg) Commenced....

My advice. Spend some of that money installing a catback exhaust with a cat delete. Then take it out of your county to be inspected as the Houston area will check your emmissions.

[mx-p5]

Hit up the local Texas section. I'm sure you'd have no problem finding some local mazda guys that could swap in a header or midpipe cat.

Check the FS sections here, they're up all the time!

I know personally, if you were local, i'd be willing to do work on any locals car. We've done 2 suspension swaps in my garage already on other members cars, and i've done my own header and exhaust swaps multiple times. lol

[fishdonotbounce]

^^ What he said. I have my stock midpipe that I pulled a couple months ago when I put the Corksport exhaust on. I put it up for sale back then and no one has picked it up so if you wanna buy it, just hit me up with a PM and I'll hook you up. :D

[slavrenz]

That makes a hell of alot more sense...my brothers got real pissed when I told them how much the shop was going to charge me for replacing the cat + labor. He told me $800 for the cat alone, and with labor would bring it out to about $1,100. FREAKIN ridiculous! If my brothers, and you guys, are right about getting it way cheaper then I'm better off finding another way. I don't have that kind of money anyway.

To be honest with you, I really didn't feel right about what that guy was telling me in the first place. Just because I'm a woman doesn't mean I'll pay anything because I don't know anything. Damnit I'm not THAT stupid! Well, anyways, thanks for the advice!! :)

Glad I could help. Be sure to check into that intake sensor code, if there in fact was one - go to Autozone, Oreilly's, etc., and they'll scan your car for free. If any codes besides P0421 show up, post them here before fixing your cat.

As far as the repair itself, if you're just looking to keep your daily driver in good shape and don't want to mess with any emissions hassles, go to RockAuto.com and order part number 16220. It is a Walker Exhaust catalytic converter, and for about $260, it will bolt directly onto your car, and come with a 5 year guarantee. You just need to get new gaskets and some nuts and bolts (be sure to use grade 10.9 or higher for metric bolts), and you're good to go. Although if your car has anywhere near 100,000 miles, I would suggest you buy a new front oxygen sensor while you're in there as well (you have to remove the front O2 sensor to remove the cat).

You can also get these on RockAuto.com - make sure you get a direct fit, not a universal sensor, and only replace the front one. This is the sensor that monitors your air/fuel ratio, and over time it can wear out and lower your gas mileage.

If you want to deal with the extra time and effort involved, I would look into some of the suggestions above about installing a header in place of your cat. But IMHO, if you're only looking for the vehicle to transport you reliably, it's usually not worth the trouble. Since you would be "deleting" your front cat, you might have to rig something else up in order to pass emissions testing.

[slavrenz]

That makes a hell of alot more sense...my brothers got real pissed when I told them how much the shop was going to charge me for replacing the cat + labor. He told me $800 for the cat alone, and with labor would bring it out to about $1,100. FREAKIN ridiculous! If my brothers, and you guys, are right about getting it way cheaper then I'm better off finding another way. I don't have that kind of money anyway.

To be honest with you, I really didn't feel right about what that guy was telling me in the first place. Just because I'm a woman doesn't mean I'll pay anything because I don't know anything. Damnit I'm not THAT stupid! Well, anyways, thanks for the advice!! :)

I'm guessing they wanted to install the OEM Mazda cat, and to be honest, sadly this quote isn't that unreasonable. Even if you go to the onlinemazdaparts.com website and buy it discounted, it'll still run you something like $700. Even at that price, with an hour installation, you're looking at at least $800 (althought $300 for labor is a little crazy, I'll admit :)).

Sure, that $700 converter will last another 10 years, but I doubt you'll still be driving the P5 in 2019, when gas is like $50 a gallon. ;)

[mx-p5]

shoot, for $500 i'll be there with bells on and my OEM header and do the swap myself

[slavrenz]

shoot, for $500 i'll be there with bells on and my OEM header and do the swap myself

Subtract $150 from that for gas to get from Florida to Texas (and back, hopefully) ;)

[racerchick]

(humpleg) Commenced....

My advice. Spend some of that money installing a catback exhaust with a cat delete. Then take it out of your county to be inspected as the Houston area will check your emmissions.

I'm seriously thinking about doing that. I already have an msp exhaust on my car. I haven't looked as much into it as I need to yet, but I just know I want more throttle. lol.

[angelito]

i have 2 problems,my p5 had a problem starting .clickc .click,click -start .i had to do this 5 or more times untill started.finally it would not start anymore.it has a brand new battery ,a new starter and still wont start.now every time i connect both battery terminals ,my mazda alarm goes on and on till i disconnect it. my remote alarm controller has a new battery also,but it wont work to turn the alarm off.it does nothing. i been looking for a alarm kill switch but didnt find it under the dashboard. what am i doing wrong? please help

[MaxPower]

I agree... buy the Walker catalytic converter from RockAuto.com and have a decent shop install it (should cost less than $100 plus the cost of gaskets and bolts). Total should be $350-400.

[slavrenz]

i have 2 problems,my p5 had a problem starting .clickc .click,click -start .i had to do this 5 or more times untill started.finally it would not start anymore.it has a brand new battery ,a new starter and still wont start.now every time i connect both battery terminals ,my mazda alarm goes on and on till i disconnect it. my remote alarm controller has a new battery also,but it wont work to turn the alarm off.it does nothing. i been looking for a alarm kill switch but didnt find it under the dashboard. what am i doing wrong? please help

(jacked)

[i12drivemyMP5]

(jacked)Not if everyone ignores that post, lol.

[i12drivemyMP5]

That makes a hell of alot more sense...my brothers got real pissed when I told them how much the shop was going to charge me for replacing the cat + labor. He told me $800 for the cat alone, and with labor would bring it out to about $1,100. FREAKIN ridiculous! If my brothers, and you guys, are right about getting it way cheaper then I'm better off finding another way. I don't have that kind of money anyway.

To be honest with you, I really didn't feel right about what that guy was telling me in the first place. Just because I'm a woman doesn't mean I'll pay anything because I don't know anything. Damnit I'm not THAT stupid! Well, anyways, thanks for the advice!! :)This one's not 800.00...http://cgi.ebay.com/ebaymotors/Magnaflow-Catalytic-Converter-02-03-MAZDA-PROTEGE-NEW_W0QQitemZ390082821502QQcmdZViewItemQQptZMotors _Car_Truck_Parts_Accessories?hash=item5ad2bf7d7e&_trksid=p4506.c0.m245

a header, hi flow midpipe with that cat & a decent catback would be much less than any 1100.00. F that.

[racerchick]

thanks alot guys!! :) you have given me so much insight and help...except for angelito...lol anywayss...I've also been wondering...I want to take off my roof rack and sunroof shield, and I know the process is tedious, but I still need the roof rack fillers. Where can I get them or are any of you wanting to sell yours? (btw, I don't have the complete rack; just the caps).