hello, first post maybe you can help. have a 98 150 extcab 4x4 w/4.6 went to autozone, the codes read po171 system 2 lean bank 1--po174 too lean bank 2. any ideas? both rear studs on exhaust manifolds are broke. would that cause the lean condition?

 

I'd look for a vacumm leak. Check the pcv line where it goes into the intake. I've put 2 of them on my truck.

 

Welcome to the forum 1998150

Good advice from lariat97.
I'd also check to make sure the MAF sensor is clean.
How old is the fuel filter?

 

If the broken exhaust studs are allowing an exhaust leak on both sides of the engine, then, yes, they could cause the P0171 and P0174 codes. The leaks will upset the environment that the O2 sensors are in and cause the readings to be wrong.

While typically an intake system leak problem, especially the previously mentioned PCV hose, you've got another strong possibility that has to be checked and repaired

Steve