Contour Enthusiasts Group Archives Forums General Troubleshooting continuing lean condition

I started a thread here a couple of weeks ago regarding codes P0171, P0174. I have searched and followed other threads but still haven't been able to find the problem. Here is the full story:
A month ago I pulled the intake, cleaned the MAF sensor and the TB and replaced the air filter. When I put it back together I inadvertantly left the small hose that runs from the intake down behind the engine. I drove about a mile with the engine running poorly before I corrected the error. Everything seemed to be OK. The CEL came on during a drive to Phoenix from LA and back right after that. Since the car ran fine, I thought it was just related to the hose being off briefly. When I returned to LA, I checked the codes, which were:
P0171, P0174, P1131, P1132 and P1151 in that order.
I cleared the codes but the CEL came back with the first two. Since then I have searched for a vacumn leak, replaced the IAC valve and checked the PDFE sensor for moisture (none). I had developed a pinging problem on hard acceleration which seems to have stopped after re-installing the PDFE. The car seems to run fine. Questions:
Is there a test procedure for the PDFE?
Could I have damaged both upstream O2 sensors in the brief time that hose was off? How do you test those?
Are there any other suggestions?
If I can't find the problem soon I will have to take it in to the dealer, I guess, cuz I have to get it smogged for DMV renewal and they won't do it if there area codes.
Thanks to all,
LLL

C'mon you guys. Help me out here. Please?

The DPFE will not cause a lean condition.

Test the PCV system, check for leaks, etc...


or


Get a scantool.

No leaks. Replaced PCV.
Will a scantool tell where the problem is or just what the code is?

A good Scantool will tell you the output of every sensor. You can watch the engine temp, MAF, TPS, O2's...
Makes things a lot easier.

And I said "test PCV system", not just replace PCV valve.
Excessive air can get to the intake that route too.
The crankcase should be under partial vacuum. Stopping PCV air should drop the idle and make the idle richer.

Roger,
If the DPFE cannot cause a lean condition, then what explains this recent thread?
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=909589&page=4&view=collapsed&sb=5&o=7&fpart=1
Can you recommend a scantool that does all those functions? I don't have a laptop so the software route is not available to me right now.
Thanks,
LLL

In rare cases I had to remove the MAF sensor from the MAF to get it real clean. Use electronic parts cleaner, not carb or TB solvent. If you have a lot of miles get rid of the O2 sensors. They wear out and will effect power and GAS mileage.
If the EGR isn't working as it should the engine will knock a little more than normal. Besides lowering NOX it cools combustion enough to lessen detonation.

The MAF may be my problem as this all started after I cleaned it with TB cleaner. I will get some electronic parts cleaner and do it again. Looks like the sensor requires a special tool for removal - sort of a hollow torx. What is that? Will I have to replace the gasket underneath it?
If that doesn't work I'll clean the EGR.
With 72K mi. it seems a little early for O2 sensors to fail - especially two at the same time. Someone told me that if car has ever run out of gas those sensors could be damaged. True?
Thanks a bunch for the advice. Really appreciate it.
LLL

Those are security torxs screws. You can get around them by using a pair of vise-grips on the screw heads.

Or you can spend $10 at Kragen and just buy the bits for your ratchet. I would suggest doing that rather than messing up the screws for good.

BTW I am having the exact same problem with my 99CSVT. Codes P0171&P0174 for about 2 months now. New 02 sensors (ALL FOUR), New MAF, cleaned TB, checked all hoses, listened around engine compartment with a stethoscope for air leaks (none to be found), sprayed TB cleaner all over intake manifold (again, no leaks to be found).

Funny thing is, My MAF sensor which I just bought brand spanking new from ford came without any gasket between the sensor part and the plastic air intake tube?! I am thinking this might be causing my problem. (Do you guys agree?) IF I need a gasket there, where could I get one or should I just make one using gasket material from Kragen?

Sorry for the long post, several questions here...

-Glenn