2000 explorer sohc, obd shows lean in both banks

I have a 2000 explorer 4.0 sohc its a recent purchase ..I found out that the motor was swapped for a sohc, it had an original ohv.I put a k&n airfilter on it and changed the oil twice... Since day 2 I have been getting what sounds to be lifter noise at a cold start ..buts disappearps after engine gets to operating temp.Nothing has fixed that this far.. now I also am getting p0171 and p0174 codes both banks lean.Could I have a dirty maf sensor..or clogged catalytic convertor? When I changed the plugs the porcelain was near melted and it always has a burning kind of heated exhausted smell? ?
The truck runs great no driving symptoms does seem to lack power.
I read that oiled air filters cause maf issues. And no I do not believe it is a vaccum. Or intake leak

OBD Codes P0171 and P0174


This code is a very common code to the Explorer Sport and Sport Trac. It is normally the elbow that is located under the throttle body. It tends to crack on the bottom and needs to be removed to examine it. You can replace it with a small piece of heater hose that is 5/8 inch. But heater hose is a quick fix.
The hose will soften and collapse causing other problems. Purchase a PCV elbow or the replacement part from a dealer. (Motorcraft KCV190)

Intake gaskets

reprogrammed PCM?

Was the OHV PCM replaced with a SOHC PCM or reprogrammed for the SOHC when the OHV engine was replaced?

Are the lean codes a recent occurrence or have they been there since the engine swap?

Welcome to this forum! I would also suspect the intake gaskets as previously suggested.

welcome aaron

swshawaii said:

OBD Codes P0171 and P0174


This code is a very common code to the Explorer Sport and Sport Trac. It is normally the elbow that is located under the throttle body. It tends to crack on the bottom and needs to be removed to examine it. You can replace it with a small piece of heater hose that is 5/8 inch. But heater hose is a quick fix.
The hose will soften and collapse causing other problems. Purchase a PCV elbow or the replacement part from a dealer. (Motorcraft KCV190)

Click to expand...

My money is on the elbow. Much easier/cheaper to check it out first anyway.

Ditch the K&N IMO FWIW.

I dont think they use the elbow you are suggesting on 2000. They use that on newer sohc sport trac, sport and ranger intake manifolds.

He only said the OHV was replaced by a SOHC, not stating what year the SOHC was from. Thus my concurrence with swshawaii.