tanbuddy

My car had a lean bank 1 and 2 code a year ago. All it ended up being was a broken pvc valve hose.

02dkbluegt

I'll keep that in mind if mine happens to throw the code again. Another day of driving and still no CEL...

rcdblink716

both banks lean is typically dirty maf, vacuum leak, fuel pressure problem. usually dirty maf

02dkbluegt

Well, 10 days later and about 400 miles and it's throwing another pair of codes at me. P1130 & P1150 "Lack of HO2S11 Switches - Fuel Trim At Limit" and "Lack of HO2S12 Switches - Fuel Trim At Limit".

I really thought an over oiled K&N was the problem before, atleast it made sense. What should I start checking next?
Keep in mind, the car is acting fine, runs strong, idles as smooth as it always has.

smitty2919

O2's? just an idea

02dkbluegt

Yea but both of them at the same time? I feel like the chances of that are slim

cliffyk

Here's what the shop manual says about P1130 (P1150 is the same)...

Where it's both banks I would strongly suspect a vacuum leak as others have suggested, or a leak in the EVAP or EGR systems. Maybe exhaust leaks...

Markus989

So i wonder is it whats called the (Long term fuel trim) working for mazda there were long term and short term fuel trims this kinda sounds a like your long term is maxxed out. and it will compensate over time for things like vacuum leaks and other air/fuel issues But it can only compensate so far before it cant anymore. You can eliminate the possibility of a vacuum leak using break cleaner( be fuxking careful of the exaust manifold) but spray the brake clean over ur intake mani and hoses with the car on. If you have a leak anywhere the car will react when you spray brake clean into the leak. It will also help pinpoint the leak. To me this sounds like your culprit this would be the fist thing i do....

Markus989

An exaust leak would defintly throw off your o2 but the car would act funny...and evaps and egrs have theyre own codes... try my brake clean method but dont catch ur car on fire!

02dkbluegt

Well to all of those who guessed a vacuum line +2pts to you. After searching for the longest time I found one of the lines had a nice crack worn into it. Of course the crack was on the very bottom of the hose so you couldn't see it just looking at it, I just happened to feel it when checking all the hoses.

I just replaced the hose and I think all should be good now. It's nice to have found a physical problem and solution.

Thanks everyone