Northstar Engines and System Technical Discussion Discussion, 2002 sts engine codes in Cadillac Engine Discussion; I have a 2002 STS, took it to Autozone and had them hook it to a computer. The car is ...
I have a 2002 STS, took it to Autozone and had them hook it to a computer. The car is sputtering, stalling, hard to get going and won't go very fast.
These codes revealed themselves when hooked to the computer. P0101, P0404, P0420.
Any ideas what these may becaused By? can I fix this myself? How much should it cost if I take to a dealership? I live in Metro Detroit area of Michigan. Thanks for anybdies help and this is a great site.
a EGR and driving it while running like that failed the CAT, you melted it and clogged it
your looking at at least 2 grand if you go for OEM parts
Woowa, slow down Jason. I would start by diagnosing the EGR first. An EGR valve that is sticking open will change the airflow and may cause a loss of vacuum that may also set the P0101 code or a lean code.
You are correct about the damage that may have been caused to cat, a misfire is the worse thing to put a cat through, they hate it, I have heard some case where a misfire killed a cat in less than a minute. But, if not melted or broken up they can restore itself somewhat, though the life of the cat has been shorten.
A restricted air intake duct
• A collapsed air intake duct • A misaligned air intake duct • A dirty air filter element • A deteriorating air filter element • Any objects blocking the air inlet screen of the MAF sensor • Any debris or contamination on the sensing elements of the MAF sensor • Any vacuum leak downstream of the MAF sensor • A poor vacuum connection at the MAP sensor • Any water intrusion in the induction system • A restricted exhaust system
All of the above can set a P0101 too. One thing at a time, diagnose and check circuits before replacing an expensive part. You also might want to try and clear all codes and see what comes back.
The OP needs to learn to pull and read his own codes. You don't need to go anywhere: the car will do it for you. The instructions for your '02 are at the top sticky threads in N* performance and Tech tips.
hey im just basing it on the codes lol
ESI confirms my diagnosis
if the car wont run and has a SEVERE loss in power along with driveability issues and is throwing a CAT code along with an EGR code, my exhaust knowledge tends to say he melted the cat and it aint a cheap one on these cars lol
I have been given a quote for the, P0101, $295.00 with tax any idea if the car will run if this is replaced? It sounds like to me that it's a wait and see if I damged my CAT or not. Should I suggest that the Cad. service techs should clear the codes first or will the look at me strange of I suggest that. Thanks again for all the helpful suggestions.
Do to the fact that the car lacks power I would drop the exhaust just before the cat and see it the problem goes away, it's quick and easy. I don't think you have a bad MAF, If you had a bad MAF then after the P0101 set the PCM would will go to a default known good value and the car would run OK. A restricted exhaust system will set P0101, drop exhaust system and go from there.
Like Jason said,
if the car wont run and has a SEVERE loss in power along with driveability issues and is throwing a CAT code along with an EGR code, my exhaust knowledge tends to say he melted the cat