Rough idle Maf or intake gasket HELP!

[phreakness]

My wonderful GF decided to let me know that her car (2002 Sport Trac) "wasn't driving right" I asked her how long Its been doing it, and she says "about a month or two, maybe longer" well she's got a CEL light that she ofcourse never told me about. So I pulled the codes with my X-cal2 and here is what I get....

P0171 SYS TO LEAN 1
P0174 SYS TO LEAN 2
P0300 RNDM MULTCY MSFR DET
P1130 LACK OF H02S12 SWT FUEL SWT FUEL
P1131 LACK OF H02S12 SWT FUEL SWT FUEL
P1150 LACK OF H02S12 SWT FUEL SWT FUEL
P1151 LACK OF H02S12 SWT FUEL SWT LEAN

So needless to say she's had a problem for a while. I've cleared her codes and I've got her car today for a 130 mile round trip. It seems to surge when in gear but not as bad when I take it out. so its surges bad at idle, seems to be fine at speed which tends to lead me toward maf or intake. but the codes make me think O2.

So what is it? O2 sensors, Intake gasket or MAF. knowing her all three would be my luck.

I can do a livelink log tonight when I get home but I'm not sure what needs to be logged.

 

[dogfriend]

P0300 is the code for random misfire in multiple cylinders. I would inspect the plugs and wiring unless they are relatively new.

The other codes are O2 sensors and/or catalyst efficiency codes.

 

[phreakness]

P0300 is the code for random misfire in multiple cylinders. I would inspect the plugs and wiring unless they are relatively new.

The other codes are O2 sensors and/or catalyst efficiency codes.

Yea the misfire is what I think made her talk to me about the car. I changed the plugs about 3000 miles ago. The car just turned 68k. I'm betting It doesnt smell rich or smoke alot. so that could be a one time thing because of the codes.

 

[dogfriend]

If those are the original ignition wires, you are probably overdue for new ones with 68K. You might want to check the resistance first, or just replace them. Also, you may want to check the resistance of the coil pack - when I was getting a random misfire it was caused by high resistance in the secondary side of the coil.

 

[ma96782]

Check for an intake leak........manifold comes to mind.

There are many posts on the P0171, P0174 codes......SEARCH.

Aloha, Mark

 

[phreakness]

Check for an intake leak........manifold comes to mind.

There are many posts on the P0171, P0174 codes......SEARCH.

Aloha, Mark

I have searched several times and all that comes up are 4 hits, 3 of them are top level results and the other talks about a 98 and a recall that I dont think covers my 2002.

I might do a tune up on her car with a new set of coil packs, wires plugs, air filter, MAF, and maybe o2's

 

[dogfriend]

I would test the coil pack first, before replacing it because a new one is about $120. The test is easy, but you will need an ohmmeter.



Also see these threads:

http://www.explorerforum.com/forums/showthread.php?t=145587&highlight=P0171

http://www.explorerforum.com/forums/showthread.php?t=148452&highlight=P0171

http://www.explorerforum.com/forums/showthread.php?t=154116&highlight=p1130

 

[phreakness]

Ok well I did a datalog of the truck and I had an o2 that was reading 0.00 so I replaced it. well that didnt fix it, still reading 0.00. I have the datalog if anyone wants to see it.

Now I'm going to look at the plugs and wires and packs. I replaced the plugs about 30k but didnt do the wires.

If that doesnt work onto the intake gaskets, and I'm not happy about that.

 

[dogfriend]

Ok well I did a datalog of the truck and I had an o2 that was reading 0.00 so I replaced it. well that didnt fix it, still reading 0.00. I have the datalog if anyone wants to see it.

If it isn't switching back and forth around .4 mV, then the signal must not be getting to the PCM. I would check the wiring carefully for damage including the connector.

I'm assuming that you don't have an aftermarket performance chip installed.

 

[phreakness]

That is correct. No tune, no chip.

I have a custom 1997 Lincoln mark VIII with a 2004 mustang cobra engine. I doo all the custom programing on it.

the connector looked fine, no burns or tearing in the connector. I'll datalog again tonight. with a focus on the coil packs.

 

[kaoshen]

The FORD service manual used at the dealships says thsi abuot each of the following codes:

P0171 - System to Lean : The Adaptive Fuel : For lean and rich :
: (Bank 1) : Strategy continuously : DTCs: :
: : monitors fuel delivery : * Fuel system :
: : hardware. The test : * Excessive fuel :
: : fails when the : pressure. :
: : adaptive fuel tables : * Leaking :
: : reach a rich : /contaminated fuel :
: : calibrated limit. : injectors. :
: : : * Leaking fuel :
: : : pressure regulator. :
: : : * Low fuel pressure :
: : : or running out of :
: : : fuel. :
: : : * Vapor recovery :
: : : system. :
: : : * Induction system: :
: : : - Air leaks after :
: : : the MAF. :
: : : - Vacuum Leaks. :
: : : - PCV system. :
: : : - Improperly seated :
: : : engine oil :
: : : dipstick. :
: : : * EGR system: :
: : : - Leaking gasket. :
: : : - Stuck EGR valve. :
: : : - Leaking diaphragm :
: : : or EVR. :
: : : * Base Engine: :
: : : - Oil overfill. :
: : : - Cam timing. :
: : : - Cylinder :
: : : compression. :
: : : - Exhaust leaks :
: : : before or near :
: : : the HO2Ss. :

AND FOR P0300:
P0300 - Random Misfire : The random misfire DTC : * Camshaft position :
: : indicates multiple : sensor (CMP) :
: : cylinders are : * Low fuel: less than :
: : misfiring or the PCM : 1/8 tank :
: : cannot identify which : * Stuck open EGR :
: : cylinder is misfiring. : valve

Simply spray some carb cleaner into intake. Also add Fuel Cleaner and at least a full tank of 93 FUEL to clean the system. This is a possible easy fix, worked on my 99 Explorer. Good luck!