Far fetched but the lean condition could be caused by a failing fuel pump, only way to see is to do a fuel pressure system test......

You are doing swell so far with the testing..... Philip

 

OK, got a fuel pressure Gage and used the connection on the frame rail r/h side.

Static i.e. just key on, had 34 PSI
Running had 28.

Also, I put in a new fuel pump relay after the fact and ignition turns the fuel pump on everytime.

Also this morning got a check oil light. Was low and corrected.

I am going to check the air filter after this input.

Will be waiting follow up and thanks a bunch.

I am thinking about cleaning the MAF but not sure what I would gain at this point.

If it still indicates a vaccum leak, I will go do that again.

 

Het Vet. I have a 1993 Cali Explorer with the updated 1994 PCM so it is the same exact EFI system you have. I have gone through all these issues (except the fuel pump but looks like to solved this). Also looks liek you solved the EGR issue. Wrong voltage probably meant the solenoid was bleading a little and opening up the EGR valve or the valve was sticking.

As for your lean codes, I'll bet my truck you need to celan the MAF sensor. Since you have both banks showing lean, the MAF is the only thing left affecting both banks. If it was a vac leak, it would have to be huge and your vac measurment doesn't show it.

I clean my MAf a couple times a year just to keep up with it. You'll be amazed at the power you get back. I've got over 230,000 miles and it runs like it is brand new.

 

I have since driven the car to Nevada, about 200 miles from here. Vehicle drove fine except for the recurring codes 172, 176. Actually got reasonable gas mileage but power was down a little. Could very well be the MAF.

I have another in my garage that I will be taking to Nevada on Thursday. Gave the car to my nephew so he can install. My other nephew will be putting Vehicle on a serious tester next week. If the MAF isn't bad, he will find the problem.

Not worried about SMOG anymore since Fallon Nevada does not require. It will get fixed anyway but that is their choice.

I took the old tranny up there also. There is another 1994 exploder in their area for $200 and all it needs is a tranny. May get that one also but I will leave the tranny replacement up to them. I have done my last.

I can now focus on my 65 Stang Fastback.

 

Nice! Is it a 390 big block? Sweet Mustang.

Your symptoms on the one Explorer with the lean O2 codes and low power is typical dirty MAF. Higher gas mileage maybe since it is running so lean.

Cleaning is easy. Just remove the 2 torx screws, disconnect the wiring connector and pull the sensor out. Shoot it with carb cleaner for 10-20 seconds, blow it dry and reinstall it. Literally less than 5 minutes. Can you believe the dealers charge over $350 to replace these things? I had 2 or 3 replaced while under warranty. No wonder Ford was loosing so much money in the 90's.

 

Right now it is still a I6-200. The car has been lost since the 70's to early 80's when it had a Maryland Serial Number assigned.

I have since gotten the original VIN reinstated and we are tossing ideas around. We might go with a 351W but leaning on keeping original except for interior/paint (Pearl).

Still not convinced which has more value since car is totally original at this point. Only has 90480 miles.

Will make the final decision when all the paint and body work is done.

I am gathering all the suspension for upgrade just in case. If we keep original, we will get another and make a ton of resto-mod changes including dakota digital, etc.