Sum-bitching truck

Grilllights · #1 08-31-2008, 04:30 PM

2002 4.2 Truck is throwing codes P1131, P1151, P1071, P1074
Idles fine, but from a dead stop taking off between 1500-1900 rpm's it will miss out and every once and a while you can hear it pop (backfire) under the hood.
Also in OD it bucks and stumbles..have to drive it out of OD on the road.

I have replaced the fuel filter, MAS, and in the process of changing plugs and wires at the moment. I have searched for vacume leaks none found so far...
Any input would be great..

novsun88 · #2 08-31-2008, 05:59 PM

It sounds like your engine is running lean.. It could be from fuel pressure, or an egr system or vacuum leak- probably on the intake system or even a MAF not reading right. I don't think its an O2 problem with this code. Like I said basically all of these codes are based around the engine running lean. I would recheck all of your vacuum lines, and since it sounds like you replaced your fuel filter recently I would check your fuel pressure. Last thing may sound dumb but did you touch your MAF? I have had similar codes on my 98. Good luck

Grilllights · #3 09-01-2008, 11:26 AM

Ok got it to stop missing out. Replaced plugs. Funny thing is had two sets of plugs in it.

Ok heres the deal with this truck I bought it back in 04 it had 38K on it. For 2years never had a issue with it not one.
Changed oil every 3K I have always took care of it.. Till I decided to put a damn K&N air filter in it..This is where all the problems started. Three months after I put the filter in it started running bad it was losing power, pinging, drinking alot of fuel and would blow alot of smoke when you got on it.
Finally throwing these lean codes. Took it to ford they said the MAF was bad due to the filter oil coating the MAF and burning it up. So I replaced it along with throwing the K&N in the trash and putting a regular air filter in it. Replaced the fuel filter It ran fine for 6 months after that then started doing the same thing..light came on lean codes started pinging, drinking alot of fuel, smoke, loss of power.

So again because Ford said it was the MAF I replaced it along with the fuel filter and the O2's. It ran fine for 3 months and started the same thing again...So I said screw it and have drove it like this for over a year.
Untill last week when It started missing out. They truck just hit 99K and yes this was the first time I replaced the plugs since I bought the truck used from Ford. I did notice yesterday while changing plugs and checking vac lines again around the front of the intake at the bottom was a small area with alot of carbon build up on the aluminum I thought it has to be leaking here but, after half a can of spraying carb cleaner around the area no drop or raise in idle...
I am stumped It runs again but as before gets crappy fuel mileage and that glowing check engine light stays on..

I have never checked the fuel pressure will try it next and see.

novsun88 · #4 09-01-2008, 05:55 PM

Clean out the MAF also just for kicks to see what would happen. Make sure to disconnect the battery and let the engine clear out. Sometimes paper filters cause the MAF to clog up over time. It takes bout 10 mins to clean it off I do it every oil change.

Raptor05121 · #5 09-01-2008, 06:25 PM

the K&N isnt the problem if it kept doing that when you went back to the stock filter.

Grilllights · #6 09-02-2008, 11:56 AM

Ahhh this truck. Well after changing the plugs it ran fine in the 3 mile test drive. Then we decided to go to the beach and it started missing again after about 12 miles of driving... Got home yesterday about 5pm cleaned the MAF after the truck cooled down drove it and once it warmed up started missing again. Going to test fuel pressure Thurday. Could this be the coil pack?