Hey guys, I have a 98 F-150 with the 4.6. Last year I put on headers and high flow cats. Now I'm blowing O2 sensors like crazy and now I have a check engine light and the code says the engine is running lean. My mechanic told me theres way too much air flow with the cats and headers and not enough fuel. He said a way too compensate is with high flow fuel injectors, high flow fuel pump, and high flow fuel regulator. My question is, will this hurt the engine in the long run? Thanks.

 

find a new mech. adding high flow cats wont lean your engine... what was the code exactly... there are many areas of an engine that casue it to run lean... an o2 will not "blow" the only thing that they can do its read wrong with age, or getting damaged before install and it will be wrong. im thinking the o2's are working fine but your engine is running lean!

 

Thats exactly it, the new code says the engine is running lean. The O2s arent the problem anymore, its the engine overall.

 

have you ever shot your maf with some electrical cleaner??? that could be a good thing to try or if you got a couple hours take off your intake, tb, and tb elbow and give them a good cleaning with sea foams DEEP CREEP arosoul can. make sure you clean the EGR ports and the Idle air control valve pretty good. if your not sure how to do this... https://www.f150online.com/forums/li...ebodyclean.php thats the best place i have found... also VERY funny. i personally got pretty PO'ed at things while i was doing it but i printed that instruction thing out and when i was ready to throw a wrench across the room i looked down and started cracking up! haha

 

Thanks a lot that looks really helpful and it is pretty funny.

 

You should do what racerf150man suggests regardless of what your current situation is then think about getting a custom chip burned to compensate for your headers and cats and gain some more horses! Fords stock set up is very conservative.
The only drawback is once you burn the chip you'll have to reburn it if you change anything. It'll probably be about the same price as what your mechanic suggested in parts.

Good Luck! Sean