SES Light Bad Gas???

[nda0602v6]

My SES light just came on recently and since the car is still under warranty, I took it in today to have it checked out. The mechanic working on it just called and said the Oxygen Sensor was causing the SES light to come on and he said I should stay away from 87 octane gas and go with higher grades like 92. :eek: Man the price of that stuff is crazy.

Is this true? I've been using 87 in this car for almost 2-months now with no problems and its been running great (no pings, hesitations, etc.). The SES light came on Monday and I had just put in a full take of gas Sunday evening...could it also just be bad gas maybe?

[Jaymatic]

The owners manual recomends 87, so this dude doesn't know what he's talking about.

[Phillip McCaffrey]

he is totally 100% guaranteed full of horse ****..

GM recomends (and someone on here had the article) to use 87. In fact, they even said that 91 wont have any performance benefits for our cars at all (stock of course). Now i dont know about the performance part but 87 is good enough. They usually say that because they dont want to be the ones to do the work so they make you go away and hope that someone else gets stuck with the job. Take it to autozone and have them read exactly what the code is. You might wanna try fuel injector cleaner and 91 to clean it out if its runnin to lean (and that prob what it is). Just my two cents, but they are full of ****

[nda0602v6]

I got the car back and the light is out now. My wife picked it up from the dealer and she said the service manager told her to use the highest grade of gas she could afford. :rolleyes: Whoever worked on the car today must have driven it all over town for hours or something cause it's on half a tank (was on full when it was brought in this morning).

The receipt of what they did reads like this: "Scanner found codes P1133 and P1153. Both codes are for Oxygen sensors called TAC. Case#7371090 said clear codes and drive car and check fuel trim all ok now. Suggest customer switch to higher grade fuel."

You guys also mentioned something about "lean." When the mechanic called me today he did mention the word "lean." I'll get some fuel injector cleaner tomorrow.

[Dan Vincent]

The dealer should have at least tested the O2s with their fancy dealer equipment. Bad O2s can make your fuel usage go all over the place (though they tend to make you run rich rather than lean when they go bad).

Seafoam it, check your intake to see if there's anything mean in it (air filter, TB, etc).

[nda0602v6]

out of curiosity, how long do 02s usally last? The car has 13,500 miles on it now.

Check air cleaner and throttle body for what now?

[99W68Firebird]

i think that everyone has been getting "bad gas" lately.. i know my car has the same problem. runs like crap, rough idle. wonder if these gas stations are doing something to the gas like deluting it. i dunno i have no clue but i have to run 93 octane cuz i have that jet chip stage 2. and car was fine for a month with it then all of a sudden get SES light and it runs like crap.. fixed after i go to a different gas station then couple weeks later same problem again, and now it wont go away, ive filled up at mobil, BP, and marathon. and still runs choppy and has rough idles. dunno what it is, was talking to kid today at work and he said his hummer is running crappy also says sounds like theres more air going into the car. is there someone or a way you can check the octane rating in the gas?

[nda0602v6]

I never had any troubles till I filled up at Marathon the other day. Prob all watered down lol

[malice10985]

only 13,000 miles? I think you bought a tank of crappy gas.

Run some good reputable 91+ octane for a couple weeks, and then switch back to 87 octane from a good, reputable gas station. I only use shell, texaco, or Amoco.

[nda0602v6]

Originally posted by malice10985:
only 13,000 miles? I think you bought a tank of crappy gas.

Yeah, a very "expensive" tank of crappy gas lol (2.05 a gal)

[Jaymatic]

stay away from Mobil and Exxon. I've been hearing bad things about them recently. A lot of people that went there got check engine lights, including my mom in her Jeep. After she was close to empty she then went to a Gibbs to fill up, and back to Mobil again. Never changed octane rating but as soon as she went back to Mobil to fill up, which was 2 weeks later, she got a check engine light again.

[wantmorepower]

And i bet you that they will continue to tell you that it's just bad gas until the warr. is up. Don't take it. GM says 87. If 87 doesn't work for you anymore make them fix it till it does.