My check engine light came on after I just put 91 octane in my truck. Kinda curious if it was the 91 octane? Which is the preferred octane to use?

BustedMJ · by **BustedMJ** [OP] » Feb 26 2015, 8:15pm

dav2no1 · by **dav2no1** » Feb 26 2015, 8:19pm

Did you tighten the gas cap? Most CEL issues after fill up is the cap. Check the codes and report back.

BustedMJ · by **BustedMJ** [OP] » Feb 26 2015, 8:20pm

That's what I am thinking. I just bought it yesterday. And I think it's a gas cap to a different vehicle. Because it just doesn't fit right. I will let you know.

dav2no1 · by **dav2no1** » Feb 26 2015, 8:28pm

Yes, let us know. Maybe your bad luck will help others. Another mistake people make is to keep filling or top off the tank after the pump clicks off. That can cause evap codes in newer vehicles.

BustedMJ · by **BustedMJ** [OP] » Feb 28 2015, 4:35am

I just put a new fuel cap for it still light is on. Going to go to a friends tomorrow to use his scanner.

dav2no1 · by **dav2no1** » Feb 28 2015, 4:41am

Right, you need to use a scan tool and reset the code. Make a note of it, so we can look it up and see if there is some other issue. hopefully it was just a bad cap!

19trax95 · by **19trax95** » Feb 28 2015, 5:10am

If you don't have access to a scanner, places like autozone will scan the codes for free.

Just make sure you ask them the code number.

BustedMJ · by **BustedMJ** [OP] » Feb 28 2015, 11:52pm

Well I went to both Autozone and O'Reillys and the computer wouldn't work on my truck. Also I used my friends and my dad's and the scanner didn't work either. Any help with that?

19trax95 · by **19trax95** » Mar 01 2015, 12:02am

Check the cigarette lighter fuse.

Wratchet · by **Wratchet** » Mar 01 2015, 12:23am

I had problems with my pcm in my 04. Nothing major, but there were underling issues like the emission cycles not testing and engine oil life wouldn't not reset. Minor things.

Given that your scan port is dead that's a good thing to have checked.