Ok I have a friend who put 87 gas in his 01 Lude. Now the check engine light is on and its running like poo. Could the gas have anything to do with light, or is that a seperate problem?

 

Jesus Christ- 93 93 93 93 93 !!

That could be a problem, but see what codes its throwing just to make sure

 

try putting some octane booster to get the octane level back up. the 5th gen runs too far of an ignition timing advance for that level of octane, or drive it out the way it is. i would definately check out the code for the check engine.

 

:doh:

I honestly couldn't tell you if the CEL is a direct result of low grade gas, but rough engine performace certainly is. Our cars have 10:1 compression, and any car running over 9:1 is considered high compression. High compression = 91 or better octane.

 

low octane = detonation. detonation = engine damage. the knock sensor is supposed to detect this and retart timing. if for some reason your knock sensor is bad then you're in big trouble. get your octane back up ASAP and pray.

the cel codes is probably:

P0300 — Random Misfire
P0301 71 Misfire Cyl. 1 Or Random Misfire
P0302 72 Misfire Cyl. 2 Or Random Misfire
P0303 73 Misfire Cyl. 3 Or Random Misfire
P0304 74 Misfire Cyl. 4 Or Random Misfire

note: if indeed one of these codes are set the cel will flicker during misfire.

 

Trust me i know that this guy messed up bad. I also told him to get some octane booster, but im not sure if he listened. So im assuming that the computer retarded the timing on his car, do you have to reset the ecu after that gas is run out or what exactly would you do, i have always put 93 in my gsr, so i have never encountered this type of problem.

 

The computer should be smart enought to detect all is good but it might take a few drive cycles to clear. If it doesn't or if you want, just clear it 1 day after filling up (you want to make sure the new fuel makes it to the injectors).