Hey guys would leaking valve cover gaskets and one broken exhaust stud on both sides of exhaust cause these lean readings. Both front O2 sensers are only a couple months old. I also had a pending P0150 once but never came back.

 

I'm also a bit curious on this one. I'm only getting p0171 and it sounds like I've got an exhaust leak.

Any help for us guys running a bit lean?

 

The correction value that the ECU can use to adjust for "wear" on sensors has exceeded 22.5%. Airflow is one thing. Start with air cleaner (replace if inspection indicates) and look over every place you could have an air leak or vacuum leak. Un-metered air is one of the things that can swing values to make this code. The PCV system should be cleaned out and in good condition. If you were just a few percentage points lower in the correction factor then no codes. More about it in the Bosch engine computer manual, link below.

 

At your mileage, if you have never changed out leas the front 02's and since you have a pending 02 failure, switch them out.
As for the 171 and 174 what and when was the last tune up along with 8 mm silicone wires and filr? Might want to check for a major vacuum leak also.

 

My front 02,s are only a few months and Bosch. I changed out my Injector O-rings because of vacuum leak awhile ago I wonder if Intake Gasket is pooched now. But will my exhaust leak and leaky valve cover also cause these codes.