I have a Ford Mondeo with a Duratec V6 2.5L engine, my problems started with some intermitent and transient engine power drops.
Turns out I had a clogged fuel filter so I changed it, the problem didn't go away... So accrding to my mechanic I needed to change the Fuel pump, so I changed it and the problem didn't go away... After some time I got failure codes 171 and 174 (Lean fuel mixture in Bank 1 and 2), my mechanic changed the pump for the second time (blaiming a possible faulty first pump) and the problem remains.
Over the weekend I had the MAF and TPS sensor replaced and replaced the main cat with a tube and the problem persist with the only difference that I haven't seen the 171 and 174 codes yet (they eventually appear after a few days)...
The problem is getting worst: Now when ever the engine warm-up and maybe after 5 minutes of driving the engine starts loosing poower, and even if I floor on the accelerator the rev's don't pick-up and after a few seconds the engine starts coughing (or farting).
I was suspecting the IMRC but it seems the IMRC fails when they don't open at higher revs (+3,500), my car gives me this problem at lower rev's around 2,000.
Will appreciatte any orientation so I can go work on my car tomorrow.
BTW, the dealer says it the Fuel pump because I didn't put the original Mondeo Part number that they sell 4x the Contour replacement I'm using, screw them both pumps are for the Duratec V5 and pump same psi's.
Sorry for the lenghty post but I'm frustrated by this month old problem that keeps getting worst.
Thanks,
