Well everytime there is a drastic air temperature change, my truck will spit out the codes P0171 & P0174, saying that Bank 2 fuel system is too lean. I have a 2001 4.2, and i have seen/heard that the intake gaskets are notorious for rotting out, and was wondering if this might be the source of the codes. Is there any kind of fix for this problem, without having to go buy the gasket set and tear down the motor?!?

thanks for the help guys!

 

I would check the plenum or upper intake manifold gaskets. I have seen some of these with vacuum leaks.

 

how intricate is this process? if its a likely weekend job, im will wait until christmas break....

can someone tell me process this involves?

 

Trace your pcv system lines, it's usually the elbow. Pin holes develope and are hard to detect at times. Always clean your MAF sensor - it's not the problem, but a dirty MAF can contribute.

 

I ran into this same problem and it started to drive me nuts.
Best advice, use the search option on this forum and type in
P0171 P0174 codes. You will find alot of info and things to check for.
The last thing I wanted to do was change out the gaskets so I worked from easy things to check and on up the list. The last 2 things I did was replace the "entire PCV Assembly (Ford-OEM $28.00) and sprayed the crap out the MAF Sensor using CRC Electronic's cleaner.
I cleared my CEL for the last time, 4000 miles ago.

Good Luck, these codes can be a pain and the list is long on what to check for.

TJKinCNY