styoung

iTrader: (4)

well last night i was driving home from my friends house and i pull on the highway like i normally do, 20-70 as fast as i can, and i set my cruse control and i look at my dash and the service engine soon light was on. so i went right to autozone and had them scan it and he said that i had a small exhaust leak. now i checked my exhaust over today and didnt notice any leaks. but i know that i have had a rattle in my muffler getting worse. could a bad muffler cause the ses light to come on?? o and all i have done to my exhaust is a hooker catback. any input would be nice. thanks.

Vertigo

iTrader: (1)

Check the AIR gasket that goes to your headers on both sides... does it make a tick sound? replace them.

ReFtheMC

iTrader: (6)

Well You Should Had Taken It In To Get Tested, Not Just You Testing It, I Think They Use Special Machines

VerySlowTA

You should always assume that the people at a parts store don't know ****.

There is no way that he could hook it up to an OBD-II scanner and discover you have an exhaust leak. If your car has an exhaust leak, you should be able to hear it. There are no "exhaust leak" fault codes.

If your Service engine light is still on, get it scanned and have them tell you what the fault code is.

1998SilverZ28

Don’t use the autozone scanners. For one thing, they are made to be a "general" type scanner and will only tell you the basic of basics. Get a hold of a "Tech 2". Its the same hand held scanner that us service technicians use (I am a technician at a Pontiac-GMC dealership). Use that to scan it and see what codes you can find and you can actually monitor things like your O2 sensors and such in live action. From what I read about your problem I can think of a few things that may be wrong.

1. Bad O2 sensors. It happens, they go bad, if the two behind the cat (or where the cat should be) go bad, it will trigger the SES light to go on, but will not affect performance of the car. On the other hand, if the two most forward (before where the cats should be) go bad, it will set a SES light and set a DTC. This will affect performance of the car because the PCM and ECM use these sensors to control timing.
2. Bad muffler or collapsed double wall exhaust pipe. I have seen a muffler that looked perfectly good on the outside, but on the inside, a sheet of metal would cover the exhaust outlet from time to time, creating back pressure. A collapsed exhaust pipe will do this as well but will be constant back pressure. The only way to diagnose this is to hook up a vacuum gauge to the manifold (manifold will drop in vacuum)or at an O2 port (O2 port will drop in pressure) and watch for a drop in pressure or vacuum.
3. Bad gasket seal(s) (includes warped or bent pipes and headers). This is generally easy to diagnose because you will get a ticking sound.
4. EGR. If your car is an 98-99 F body you have an EGR valve. This being stuck open/closed will set a code and generally the engine tends to run rough.

That’s about all I can think of for exhaust codes. Hope that helps. Good luck.

ghardester

What was the actual code number? It could be as simple as not having the gas cap on tight. There isn't a code that says 'small exhaust leak'. Rattle in muffler could be a CAT going bad, which they do, and might be covered under a new extended warranty recall. Search on that too. GM will replace the CAT up to 100,000 miles I think. A lot of them are going bad.

2001NBMZ28

Do you have the actual code? If not and they cleared it wait for it to come on again.

SStheBest

iTrader: (2)

lol on stock cars most exhaust realated issues is for the "service vehicle"....unless its ur O2's

styoung

iTrader: (4)

i dont have the code, and i agree not to trust autozone. will the dealership scan for free? also the car only has 53,000 miles on it if that helps.

styoung

iTrader: (4)

i think it could be my muffler because i can hear a rattle inside of it.

styoung

iTrader: (4)

well just got back from the zone and got the code P1416, says air system bank 2 fault. i guess this means its time to remove the air pump. any ideas? thanks

2001NBMZ28

Dealers normally won't read codes free - they'll charge a "diagnostic fee." If it comes back on just get the code read again and post it.

styoung

iTrader: (4)

just did P1416

2001NBMZ28

OK, P1416 is usually just a clogged passenger side air check valve - easy to replace yourself - check to be sure no leaks at the metal air pipe at the header/loose air hose on the backside of it. GM PN is 12565503 but available at your local parts store. Has nothing to do with your muffler rattle.

styoung

iTrader: (4)

^^^thanks will check that out.

styoung

iTrader: (4)

does anyone know if i could just remove the air pump and get it tuned out if that will solve my problem??

BAD2000TA

iTrader: (6)

Short answer - no. You'll have more codes, but you can have them deleted out of the computer. But, that's going to cost you whatever a tuner will charge to delete your codes. For example: MTI here in Houston charged me about $100 to delete the EGR code after swapping an LS6 intake on my old 2000 Trans Am. I'd say it's cheap to just fix the problem. Like mentioned earlier, probably just a stuck AIR valve. They're cheap at the dealer. Do a search on the code. See what other have done in the past. Good luck.

craze4speed

iTrader: (12)

i agree on the AIR check valve that is the problem for that code 99% of the time

2001NBMZ28

GM list for 12565503 is about $38 now, should be half that at a parts store.

styoung

iTrader: (4)

well i dont need a inspection sticker and are hopefully buying headers by the end of the summer so i hate to spend the money on something i dont really need. and when i buy headers i plan on getting the offroad ones.