I have a 98t/a that was sitting for about a year , I have 40k miles so far and a new battery after sitting . I went to take it out for a ride and it was fine at first then it started running rough and had no power to get up the road . I thought the car was going to stall out on me. It feels like the car dropped a cylinder or bad gas from sitting a while. The SES light is on of course could never get it to go out since I put the headers and the cat-back system on the car with the 02sims. Is this causing the problem the o2sims are bad or is something else in the engine bad , god I hope not I am saving money for a new camaro ss when they come out. Help me Please . Thanks in advance.

 

Put a fresh tank of gas in it with some fuel stabilizer, then change out the 2 front oxygen sensors, and if you want to, your sparkplugs. I have a feeling you just need a tune up. I'm willing to bet any non-header install related code are misfire codes. The O2 sims don't effect performance at all (unless they are plugged into the front bungs) they are only there for emissions purposes to make sure the convertors ae doing their jobs.

 

This may sound crazy but on my SS when I start it after a new battery i have to start it and then turn it off and start again or else my car runs just as you describe.

 

Well, now that I think about it, and influenced by the post above me, you might want to try this, it's free, and it might work:

http://www.obdii.com/drivecycle.html

and if you can scan your codes:

https://ls1tech.com/forums/generation-iii-external-engine/509539-water-got-up-intake-what-now-all-diagnostic-trouble-codes-dtcs-inside.html

 

the first time i stored my SS it acted like that after i took it out. I let it idle like that just long enough to charge the battery and it ran like normal after another start or two. I think the computer requires a certain amout of energy to keep some things stored in memory etc, and if you leave it set beyond a certain amount of time it takes a few starts to get everything reloaded. Just my opinion and i dont know ****. Computer controlled cars are weird like that sometimes. Just dont drive far or hard and your not hurting the car.

 

one thing i remember in particular was that it would requre a certain amount of throttle at idle or it would run rough and like 3-5 hundred rpms lower than normal.

 

So my o2sims should still be good , just check the battery for a full charge and maybe put some new fuel in the car. Would the stale fuel make it run rough, almost like a cylinder was down. I will look at the spark plugs and wires to make sure they are good . I did put new spark plugs in 2 years ago , there is only about 600miles on them since. I installed the acdelco brand is thee another brand better that you would recommend?

 

I like the ngk tr55 plugs.. I think hoestly just do the relearn prrocess and drive through it with new gas and fuel stabilizer and injector cleaner.

 

Moving to General Maintanence & Repairs section....