Check Engine Codes

[ELA V8]

My check engine light came on yesterday. The three codes read banks 1 and 2 too lean and cat below efficiency.
A few months back I got a flashing check engine light. When I tried to read it it said error or something, it wouldn't pull a code. My truck started idling really rough, and I was busy with college and working so I just ran some fuel treatment in it and changed the fuel filter. It has been running better since then. I can't remember if the light went away on its on or if I cleared it.
Anyway today I cleaned the MAF sensor, throttle body, ran some more fuel treatment and cleaned and oiled the CAI (Spectre intake. ******. I've read a lot of bad about these types of CAIs. It was on the truck when I bought it, may switch it back to stock one day.) Should've just cleaned the IAC while I was in there. I cleared the code, and cleaned my battery terminals while I had them disconnected. Is there anything else I should check or clean up? Or just wait it out and see if the light comes back up? The truck seems to be running ok, maybe a little lacking in power and mileage, but the 4.6 and BFG MTs don't help that. Maybe a 351 swap would help the power part, haha.

97 exp, 4.6l

 

[CARO'S98EB]

I would double check for a vac leak first. then the most likely problem is the MAF sometimes cleanign will fix it but sometimes not.

 

[JUST4FUN]

http://www.expeditionforum.com/showthread.php?t=4926

 

[ELA V8]

Thanks guys.

Today going very slow turning left into a parking lot the engine died and the steering wheel locked up. This is the second time this has happened. The first time was going slow making a left u turn. Engine cuts off and takes about 3 turns to start. First couple turns nothing happens like a dead battery, then it cranks over. Where should I start? I'm thinking battery and cables. My volt runs low and my terminals get a lot of corrosion on them. Even after cleaning it comes back fairly quick. Check for vacuum leak, clean IAC. After that, maybe a failing fuel pump?

 

[bnegaard]

I would definitely check the fuel pump pressure. If the pressure is low it could keep running intermittently while lean. The low fuel pressure would result in a lean condition which the computer would try to overcome. Once it was far enough out of spec you would end up where you are now. Expeditions have had problems with the fuel pumps over the years. Be careful with replacements. Don't skimp or you will likely have problems down the road. (Been there done that). I would only go name brand or ford replacement parts.

 

[ELA V8]

I would definitely check the fuel pump pressure. If the pressure is low it could keep running intermittently while lean. The low fuel pressure would result in a lean condition which the computer would try to overcome. Once it was far enough out of spec you would end up where you are now. Expeditions have had problems with the fuel pumps over the years. Be careful with replacements. Don't skimp or you will likely have problems down the road. (Been there done that). I would only go name brand or ford replacement parts.

I will test it. I should note this hadn't happened often. Twice in a little over a year since I bought it. First time was very soon after buying it and now a year later. I cleaned the iac valve, the truck seems to crank over easier and has a consistent idle. I bought it cheap and I wanna see how long I can keep it running, 180k so far. I only use Motorcraft parts if they're produced. Otherwise I'll use a quality part, don't care what its for.