2002 F150 FX4 SC (5.4)

Recently replaced the battery (1st time, 98k miles) and unknowingly didn't perform the "relearn" process as described in the owner's manual (pg. 256). The truck ran fine for a day, than started having issues (i.e. rough idle, engine hesitation during acceleration). I pulled trouble codes P1504 (IAC), P0171 (B1 too lean), and P0102 (MAF). Took it the dealer, they ran diagnostics and found the same codes, but wanted to run a "cold start" diagnostics the next day, which I haven't had done yet. In the interim I read about the relearn process for idle and fuel trim; which the dealership failed to mention. I disconnected the battery to reset PCM, and went through the "relearn" process per the manual. The truck still has the same symptoms as described above.

Question: How long does the "relearn" process typically take to complete (i.e days, miles?), and is it typical for trouble codes to register during the "relearn" process?

Note: I had none of the above problems prior to replacing the battery (resetting of PCM). The dealer wants to replace the IAC and fuel filter and test the air intake for leaks. I'm thinking of giving the "relearn" process a couple days before taking it back to the dealer.

 

The evap monitor takes the longest to run (30 minutes). After that the monitors should be complete and if there is a failure somewhere you will get a code. If the monitors dont complete you will get a p1000 code until they are done. Start with the easiest action first. Check the MAF to make sure the little sensor wires are intact, clean the MAF, with almost 100K the IAC valve may have bit it but you can still take it off and clean it, B1 too lean is unmetered air typically from a vaccuum leak or a leak around the downstream (furthest back) 02 sensor. Check your hoses for degradation and any possible leaks. It is possible that the IAC and MAF failed at the same time (although unlikely). You check the fuses? GL