SES light and rough idle

**Hedghog** · 07-11-2008, 09:45 AM

I just purchased a 2001 Trans AM WS6 convertable and have a question about my SES light and fault code.

I drove it for about 400miles from the seller to my home. After about 350miles the SES light up. Idle become rough.

I continued to drive home the last 50miles and let it stay over night. When I started it in the morning the SES light was NOT on any more. But after about 20 min of driving it come on lighting again. Rough idle again...

When reading the fault codes there was three of them:

* Something about O2 sensor
* Something about O2 sensor Bank 2
* Something about missfireing on cylinder

After the service shop cleared the codes and shut off the SES light the idle become stable again and when reading the OBD2 tool "live" both O2 / lambda showed normal values and no miss fireing.

I have driven about 150miles after this with everything OK = no SES light.

ANy ideas what it could be?

**jprice** · 07-11-2008, 09:57 AM

could be your cats gm has an extended warranty on them 10yrs/ 120,000 miles if they fail a dealership will replace them free just gotta let them know about the warranty alot of dealers arent aware of it

**jprice** · 07-11-2008, 09:59 AM

and its gotta be tested at the dealership and they determine if its warranty work or not forgot to put that in their good luck.

**ajs1978** · 07-11-2008, 12:13 PM

From what I've found, O2 sensors are always showing up on SES codes. Chances are, you need new plugs and wires. Mine were replaced around 45k with Autolite plugs and NGK wires. 30k and 6 years later, still no miss.

Change your plugs, maybe even your wires. #8 is a biotch but still doable.

**iam_dale** · 07-11-2008, 12:59 PM

What kind/grade of gas did you put in it?

dale

**Stricken1** · 07-11-2008, 02:19 PM

If its PO Code 300-308 its a misfire on that cyl. Find out what code its throwing and post it up. Most of the time you might be throwing a to lean or to rich code in the left or right banks.

**Hedghog** · 07-11-2008, 11:50 PM

I live in Sweden and we have only 95 or 98 unleaded to gas up with. I used 95.

The car is going good right now with nice idle and everything. If SES light up again I will let the mechanic write down the code and post it.

Will it be bad driving my car now without doing anything?