used motors ca/fed egr/no gr

[coopab]

I'm thinking of replacing my motor in my 99 Ranger 4.0 but have a couple of questions. To start with, the existing motor is a used motor with a label that says 2000 EXPL, so I assume a previous owner replaced the original motor.

Car-Part.com shows four options based on emissions standards including whether the engine has or doesn't have an EGR valve.

The sticker in the engine compartment indicates the truck was built to CA emission standards and the non-original motor does not have an EGR valve.

Here's the questions: If the original motor DID have an EGR valve, could the lack of an EGR valve be the source of my P0171 lean code? Is there any way to determine from the VIN whether the original engine had an EGR valve or not? Since I know that the original engine was CA emissions compliant, would I be OK with either engine with or without an EGR valve, as long as I get a CA compliant engine?

Although I am dealing with that pesky P0171 code a motor swap seems inevitable due to severe oil usage, both burning and leaking.

 

[RonD]

Assuming 4.0l OHV, the 4.0l was redesigned to an SOHC(Single Over Head Cam) engine around this time.

P0171 wouldn't be from the lack of an EGR valve.
EGR system is used to cool the cylinders when under load, helps prevent pinging, also reduces emissions.

The PCM(computer) was probably swapped with the engine or you would get EGR fault codes since it isn't there.
The P0171 is set by readings from the O2 sensors, but doesn't mean an O2 sensor fault.
PCM has limited preset parameters allowing it to richen the fuel mix, so it can not just dump in enough fuel to eliminate the O2 sensors report of lean mix.
P0171 is usually reported because PCM has reached its preset rich limit, so it is reporting the problem.
Could be MAF sensor or air leak, the rich/lean preset parameters are based on the air flow, if "unreported" air is coming into the engine then PCM reaches it rich limit but fuel/air is still lean, so it reports the problem.
It could be the O2 sensor as well, burning oil will shorten the life of O2 sensors.
But replacing O2 sensor in an engine that's burning oil would be a waste of money IMO.

If your location doesn't require EGR or emission testing then I would swap for what you have now.
And replace O2 sensors at that time.

 

[coopab]

It is the OHV engine.

Both upstream O2 sensors have been replaced in the slightly over a year's time that I've owned this truck.

I had two misfires until recently (0304 and 0306) and they seemed to have been cleared up with new plugs, wires, and a coil pack. However after passing the inspection a week or so ago the codes returned. The P0171 showed as a "pending fault" until after the inspection, but when it returned it became a "current fault."

I've tried to identify air leaks with carb cleaner/brake cleaner sprayed around the intake manifold and vaccuum lines w/o any success. I'd like to solve the P0171 to see if it clears up the misfires.

Massachusetts annual inspection used to sniff the exhaust but now relies on the OBDII. For a vehicle 2000 or older it allows two "not ready" monitors. Since I managed to pass the inspection in August, I'm OK to drive it for another year and if I could solve the P0171 I would take the time finding a good used motor. In the meantime the lean condition and misfires on cyls 4 & 6 are showing up with a flashing CEL at times.

If I go ahead with a motor swap now I'd go for the lo emissions (CA) with no EGR valve. If the previous motor had an EGR valve then the computer (pcm) must also have been swapped at that time?????

Thanks for quick reply.