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Old 01-01-2011, 04:14 PM   #21
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A clogged cat would prevent flow out and make the engine run rough and loose power. Not sure if it will throw a MAF code.
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Old 01-04-2011, 06:25 PM   #22
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OK, the idea of a clogged Catalytic converter made all the sense in the world. My MAF has been replaced, the wiring and fuses all checked, so I am convinced that is NOT the problem. But air flow is the problem. After reading this and talking to some colleagues, I tried this. I removed the pre-cat oxygen sensor.....the only one.....and tried running the car with that as a temporary exhaust bypass......low and behold, the car ran, up to and including highway speeds (before, I couldn't even drive it up my driveway and if it was operating temp, couldn't even restart it).

So it seems that this test proved the cat flow COULD be the problem. Still getting a MAF error, but if the CAT is clogged, maybe the flow still isn't good enough???

What are thoughts on this trial method? Next question is, should I replace the cat or simply remove (hey, I live in the sticks).
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Old 01-04-2011, 06:30 PM   #23
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That'* how you test the cat. Correct that problem and the other code may go away.
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Old 01-04-2011, 10:20 PM   #24
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Sometimes you can't see the MAF tree cause of the forest. Makes sense to me given everything you've done and the obvious improvement. Low air flow with throttle other than idle can throw a MAF fault. It'* reading what the ECM decides isnt right given the TPS setting. And hasn't a clue you have an obsruction. Most converters have many "tube'*" and when they clog it'* all at the same time. I'd bet the improvement of removing the O2 sensor will turn into a fix upon removing the cat. If you live in an area that doesn't have tight inspection laws or emissions testing, why bother. Of course that'* not "advice" , but what I personally would do. I'd rather be polictically incorrect than lie.
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Old 01-05-2011, 01:16 AM   #25
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You can pick up a high flow cat for $60 or $70, not a bad price.
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Old 01-05-2011, 01:55 AM   #26
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Another way basically what John said is to put in a ''test tube'' in place of the cat to see if that is your problem
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Old 01-08-2011, 01:57 PM   #27
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Yanked out the cat and put a straight pipe in its place for "testing purposes". Car is now drivable, but I am still getting that darn MAF sensor code.

Something somebody warned me about driving without the cat and that is running too lean? I know what running lean can do to an engine, but since this car has the O2 sensor BEFORE the cat (in exhaust maniford), would the ECM still run a lean fuel mixture?
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Old 01-08-2011, 02:25 PM   #28
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Quote:
Originally Posted by gamarines2 View Post
Something somebody warned me about driving without the cat and that is running too lean? I know what running lean can do to an engine, but since this car has the O2 sensor BEFORE the cat (in exhaust manifold), would the ECM still run a lean fuel mixture?
If you have your O2 sensor screwed into your exhaust, you shouldn't have a problem with the O2 sensor. Your car shouldn't have any problem running it without the cat in place since all your O2 sensors (only 1 on your car) is before the cat.

Some MAF cars have a burn off relay, but I didn't find one for your car on any auto parts sites.
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Old 01-08-2011, 03:05 PM   #29
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You said you changed the MAF and same problem? If so, inspect teh plug. Had a car a while back that had a damaged plug causing MAF codes. Was a loose connecting on the wire. Crimped it down and problem was gone.
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Old 01-08-2011, 09:25 PM   #30
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Oh, yeah, I thought that might have been the problem early on so I replaced the pigtail (soldered the new one on). Got good ground and 12 volts with ignition on.....didn't know what to look for on the yellow wire, but if the ground and hot are good, assuming the yellow (to ECM) is good as well.
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