Mechanics

COULD IT BE A CLOGGED CATALYTIC CONVERTOR?

2001 Ford Explorer • 130,000 miles

I have a 2001 Ford Explorer Sport with about 130k miles. About three months ago it started running very sluggish and at times even backfires. I ran the codes on it after the check engine light came on and got P0102, P0172, and P0175. Basically the engine is running rich on both banks and it's sensing a MAF low sensor fault. I have changed the MAF, all spark plugs, and the idle air control valve. It's killing my gas mileage and causing terrible acceleration. Please can anyone help me out here - I'm stumped. Could it be a clogged catalytic convertor?
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Brandonlee
July 29, 2012.




Anything is possible lets rule the cat out take it to a exhaust shop and have them do a back pressure test. Also have you checked the fuel pressure yet?Do you have a scan tool that reads live engine data?


Saturntech9
Jul 29, 2012.
Thanks for the prompt reply Saturntech. I do believe that my dad's reader can give me live engine stats. Let me run a test on it and I'll post the results. As for the back pressure test - I should be able to take it in for a reading sometime this week. I had seen where a small hose near the oil fill cap has caused some owners headaches but mine is fine with no cracks or splitting. What stumps me is the low MAF sensor reading - especially since its new.


Tiny
Brandonlee
Jul 29, 2012.
You could have a wire issue a terminal issue or a computer issue causing the low maf reading its not always the component causing the code. So see if you can read the maf reading on the scan tool.


Saturntech9
Jul 29, 2012.
Okay here's the live engine data from about ten minutes ago. I ran a complete set so there is a lot of data.

FUELSYS1 CL
FUELSYS2 N/A
ETC (DEGREES CELSIUS) 60
SHRTFT1% -18.8
LONGFT1% -22.7
SHRTFT2% -23.4
LONGFT2% -21.1
RPM 760
VSS 0
SPARKADV 16
IAT (DEGREES CELSIUS) 43
MAF (G/S) 9.24
TP% 20.4
O2S B1SI2 - B252 G
O2B1S1(V) 0.835
SHRTFTB1S1(%) -23.4
O2B132(V) 0.750
O2B251(V) 0.841


Tiny
Brandonlee
Jul 29, 2012.
Lets start with what I posted let me know what you find.


Saturntech9
Jul 29, 2012.
I'll take a close look at the MAF and surrounding area/hoses and get back with you. Thanks for helping me out on this!


Tiny
Brandonlee
Jul 29, 2012.
Your welcome thats what were here for keep me posted.


Saturntech9
Jul 29, 2012.
On your post above - these tests can be performed with the scan tool I used to get the live data? I've been on duty the last few days and will get to look more into the MAF tomorrow when I get off.
AD


Tiny
Brandonlee
Jul 31, 2012.
Alright keep me posted.


Saturntech9
Jul 31, 2012.
Okay here's an update on this issue. I finally got a few days off from work yesterday and today and got a chance to do some investigative work. I checked the tube that supplies air to the throttle body and it was in good shape. Grabbed a can of ether and did the poor man's vacuum leak test but that too didn't indicate any leaks. My uncle (GM mastertech) came in from AL on vacation and ran a live test to watch the voltages to the MAF both at idle and under load. At idle we were getting 11 g/s and ran her up to about 2500 - 3000 rpm. Guess what? The reading didn't move a bit! Turns out the MAF was bad. All other readings read good including o2 sensors. I have since installed a new MAF and it seems to be running much better. I'll post back in a week after putting a few more miles on it.


Tiny
Brandonlee
Aug 12, 2012.

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