Check engine Light and ETS light on a 96 Grand Am SE 2.4L?

Question

Last week when im driving my Check engine light and my ETS light come on at the same time. I went to Auto Zone and i checked the computer and the code that came up was P0420 it said that the catalyst system was preforming below efficiency bank 1. They said this is the O2 sensor and i replaced it and reset the computer and the light went off for 3 days. Then the same 2 lights came back and i didnt know what was going on. So now my car is going through about 1/8 a tank a day now. My buddy who works for a dealership says it might be the spark plugs that need to be replaced and i dont know if this will fix it (other problem is i know how to do this but im without a tourqe wrench so i cant do the job while im here in LA) So if there is any techs out there that work for GM and could lend a hand to let me know whats going on i would be greatfull. I used to work as a porter before for two dealerships so if you guys can help me her in the LA area it would be great.

Thanks,
Sean
You can IM me

Answer 1

I own a shop, and can tell you this; The first thing I would think is the new sensor wire came unhooked. I have seen this before. The wire/wires not being plugged together right, came loose, and fell apart. Have someone at Auto Zone pull the codes again, to be sure it is the same code. Bad spark plugs could be the problem, but I would lean more towards a stopped up cat/converter needing replaced. It sounds to me like your best bet is to take it to a shop, and have them make the repairs. I doubt you will find many (if any) technicians in your local area on here. You might get lucky.
Glad to help out, good Luck!!!

Answer 2

Okay once again I feel I must correct all the misinformation that the so called "master mechanic" posts.
1. The first shop you took the car to ripped you off by selling you an O2 sensor. The P0420 code sets when the system detects that the catalytic converter it not storing and releasing oxygen correctly. If the O2 sensor is bad, it will set an O2 sensor code.
2. If the new O2 sensor became unplugged, it would set a host of other O2 sensor codes such as insufficient activity, and heater circuit fault.
The code you have is setting because something has poisoned the catalytic converter causing it to not work any more. Any competent shop can test the converter with a bar 5 gas analyzer.

I cannot believe how many people out their claim to be "Masters" that don't have a clue how a car works.

Answer 3

I have a 01 Grand am and it is doing the same thing PO420 code if you replaced the O2 sensors then its probably the CAT. I have found out the for some reason every time the check engine light comes on so does the ETS light I was told there is nothing wrong with it it just trips the light when the check engine comes on. You can buy a new CAT for like $40 ..it should fix it

Answer 4

This car has 2 oxygen sensors on before the cat and one after the cat ,now the scan tool tells which position O2 sensor is at fault. You could have replaced the wrong one.also the person deciphering the readings from the O2 sensor can determine if the catalyst is doing its job or not

Answer 5

quit by way of an vehicle aspects save and function them test the laptop. The CEL will set a code that the scanner can study and enable you recognize what's misguided. maximum vehicle aspects shops will try this for loose.

Answer 6

sounds electrical LA is hot lived ther 18 yrs or could be a map sensor,or throttle position sensor

Answer 7

Hi,I think you have 2 problems as your chk engine light & your ets (traction control lamp are coming on.No quick answers except take it to a gm dealer,(maybe more xpensive but less headaches as you already have.)Sorry no quick diag.Good luck