Getting the following trouble codes on my 97 XLT 4x4 w/167,000 miles:

P0171 System Too Lean - Bank No. 1.
P0174 System Too Lean - Bank No. 2.
P0302 Misfire Detected - Cylinder 2
P0306 Misfire Detected - Cylinder 6

I replaced all 8 spark plugs. Replaced the spark plug wire to #2. Cleared the codes and still getting these 4 codes after driving for a while. It still runs like crap, so it is misfiring. What should I try next? I'm assuming that I need to clear up the misfires before worrying about the lean condition?

Dean

 

Changed the spark plug wire and plug on #6 and that fixed the P0306. The old wire didn't seem to seat onto the plug firmly, popped off and caused the misfire.

After searching throught the forum decided to check my PCV hose for leaks. The PCV hose was hosed (no wonder I had that loud sucking sound coming from the passenger side of the engine). Stealership was closed until Monday so I couldn't get the real PCV hose assembly. Went to AutoZone and purchased heavy duty PCV hose and routed it away from heat. That seems to have taken care of P0171 and P0174.

Wiped the codes and went for a test drive. Well, now I just have a P0302 code and it is running better though I can still feel a slight miss. I have changed the plug and wire to #2. What can I try next, the injector?

Dean