bossman15

My mpg has gone down from 15-17 to 11-13 and i tripped a cel today. the gas cap might have been kinda loose as i filled up last night and spilled a bit of gas as i pulled the nozzle out and quickly cleaned it up drawing my attention away from the cap. I am thinking this might have been the issue and i am going to clear the code and see what happens, but how are these three codes related? the last two are the lean in bank 1 and 2 and the po451 is an evap emission control system issue. any body have any experience with this?

kifels

I too have had the same loss in MPG. but I dont have any codes. I believe the issue is because of the winter blend of gas, I have tried 87 octane and 91 octane, no difference. I guess Im just going to wait untill the summer blend of gas come back out and see if there is a difference untill I freak out about it.

Mod (Ret.)

Simply type in the codes in Google search. You'll find out what they mean, other related codes, and what to do to repair/clear.

It's just that simple.

Tony Raine

i noticed a code with similar description on 2 Chryslers and 1 Chevy at work (sometimes i work in the campus Motor Pool). turns out they were caused by leaving the vehicle running while filling up with gas. yours may be similar.

bossman15

Yeah didn't do none of that and yes I know how to find code descriptions, that's not what I asked about, I asked how they are related and if anybody else had experienced it.

CrashTECH

Octane rating won't have any effect on MPG.

The last two codes are both engine lean (bank 1 and bank 2) the other is likely due to fuel pressure. I can see how they'd be related.

bossman15

Reset the code, tightened the cap, all seems well for now

CrashTECH

Could the gas cap really cause the lean codes?

kifels

genneraly no, usually a loose gas cap will cause a system EVAP leak (small).

a CAI has more potential to cause a lean code than a gas cap, but it could be a bad or dirty injector(s) or a bad MAF (genneraly you will have more issues with a MAF), and a bad O2 senor could cause you to get a lean code.

Mod (Ret.)

Again, Googling the codes would tell you this, provided you read through the posted results.

As to anyone else experiencing them, that is a good question to ask for sure.