DTC P1102 after new oil cooler

[fuzzman]

I'm getting a CEL and trouble code P1102 (MAF sensor in range but lower than expected) and I can't seem to track down the problem. I changed my oil cooler and when I was done I started getting P1102. I also got this code briefly when I first bought the truck about four months ago, I cleared it, and it never reappeared until after the oil cooler. Now it wont go away. I'll give the history of the work I did after describing what I have done to try to diagnose the code. First I cleaned the sensor with electrical contact cleaner, no change. Next I tested the harness for voltage. I didn't know what I was looking for, but found between .4 and 13.2 volts accross the 6 leads to the sensor at idle. I probably should have checked resistance or continuity for the sensor itself, but that's all over my head. I did check the six leads from the sensor for voltage while at idle and found Zero. I have a Dashboss monitoring system and it has two MAF related PIDs, one for voltage and one for flow in either grams per second or pounds per minuite. Both PIDs are reading zero under power at all speeds. I replaced the MAF sensor with one from a salvage yard (after cleaning it with electrical contact cleaner) and no change.

I'm having no driveability issues, except for sputtering for a few seconds when the car if first started. (I did a FICM rebuild a few months ago and my voltage is in range).

What do I do next??

The history I promised mostly in order of occurrence:
The truck has no CAT
I did the zoodad mod to open up airflow prior to the air filter when I first got the truck, no problem for a few thousand miles until I changed the oil cooler
CCV reroute to route crank case gases to a canister and then back to intake
FICM rebuild solved driveablility problem
High ECT vs. EOT led to a coolant flush. Did reverse flush, restore, then restore plus and filled with Zerex ELC CAT1
Still high deltas so new oil cooler and bulletproof egr cooler (I have smog in California) My temperature deltas are much improved, but still a disappointing 10 degrees.
Terrible drivability after oil cooler change until I purged air by driving WOT on freeway for a few minutes
Cleaned EGR valve manually (rags and q-tips) but did not use any solvent
Cleaned intake with a pressure washer
Added fuel pressure gauge
Put BB behind fuel spring to increase pressure (similar to blue spring mod). Fuel pressure climbed to 67 at freeway speeds
Wasted IPR during oil cooler change and had to replace
Cleaned & serviced Turbo while out
Had Turbo in and out 3 times (oil cooler, fouled up connection at EGR to exhaust, then for IPR) got pretty good at it
Tuned with SCT tuner that has canned tunes. Using canned tune Performance mode with high idle, and EGR off. Don't think I had an MPG gain, but throttle response, lag, and shifting are all significantly improved. Had trouble code before and after I started using tuner.

I think that's everything. Hopefully someone can help me out.
Thanks!

[dannyboy950]

I would check for an air leak at manifold or air ducts to turbo. Check your filter for restriction. An air leak after the maf can still affect your maf reading by deceaseing the air being drawn thru the maf because it is sucking air from somewhere else.

[fuzzman]

I had the filter out yesterday, and it looks good. When I reinstalled I double checked the air intake to the turbo, and it looks good too. Do you have a recommendation for how to check for leaks at the manifold? I can't see, feel or hear anything at idle.

Thanks for the reply, I've seen your posts elsewhere and you seem to have great suggestions.

[fuzzman]

Well, I was hoping for more response....

I tried a few more things, and here is the latest.

I checked MAF sensor voltages at the wiring harness, all is within specification.

I'm hunting for a leak in the intake system, somewhere between the Air Filter and the intake manifold. So, I figured a way to pressurize the system with my air compressor and listened for air escaping. I made a cap out of a PVC plug that fit into the intake duct that leads to the turbo, then I put a schrader valve in the cap. I filled the system with air and listened for a problem. My system certainley isn't air tight, it wouldn't hold pressure (about 8 psi) for more than a minute or so. I'm not sure if it should or not. I did try loosening the clamp that secures the intercooler duct to the air horn to see if that part was getting pressure, and sure enough it released the pressure that had built up.

I tried listening, and I used soapy water to try to see evidence of leaks. I couldn't really spray much of the intake manifold, much less see any bubbles that might form around the gasket.

So, am I missing something obvious?

Another layer to my problem. I can just build a custom tune that ignores the code (even when returned to stock). I would much rather find the source of the problem, but I gather the MAF sensor doesn't really gather meaningful data on the powerstroke anyway. I am getting crappy mileage, and suspect the code might be pointing me at whatever is causing mileage losses. On the other hand, I just started using the canned tunes that came with my SCT, and maybe I shouldn't have expected an increase in MPG.

Would ignoring the code with a custom tune be a bad idea?

Thanks for any input.

[mhatlen]

I am in Elk Grove, we can swap maf and test what the voltages are coming in and out on my truck. Let me know........

[fuzzman]

I really appreciate the offer! Do you have a way to read MAF voltage? My PIDs are not live for that option in my Dashboss system.

Great to hear from someone so close!

[mhatlen]

Yea I have a scanguage that will read pretty much everything. I have always had a weakness for tools just need to clean my shop so I can find them.lol

I am usually off work around 3:00 send me a p/m if you want to look at it, tomorrow or Thursday.

[fuzzman]

I just remembered something! When I did my oil cooler I may have twisted up the round wire mounted to the rear driver side intake bolt. Maybe that is the ground used for the MAF circuit....

Anyone know which if the six pins in the MAF harness is the ground?

Thinking I can check continuity if I know where to check.

Thanks!

[mhatlen]

Originally Posted by fuzzman

I just remembered something! When I did my oil cooler I may have twisted up the round wire mounted to the rear driver side intake bolt. Maybe that is the ground used for the MAF circuit....

Anyone know which if the six pins in the MAF harness is the ground?

Thinking I can check continuity if I know where to check.

Thanks!

Terminal (C) is: pwrgnd
If you send me a p/m I will send you a Ford Service/Diagostics for the 6.0 and it is full of good info as well as wiring for it.
Mark.....