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Discussion Starter · #1 ·
Ok first off I know I know, air fuel gauges tell you nothing, but my car runs horribly when the signal on my air fuel gauge goes away. Car runs great when it is in the Green, ie rich, great when in yellow ie stoch, and ok when it is in the red ie lean. But alot of the time the signal goes away and the car seems to be robbed of power. That has happened for awhile now. But here in the past few weeks the car has started misfiring or stuttering. Almost sounds like it backfires sometimes, but not out of the exhaust. Its at the shop right now but the mechanic and I are stumped. Please help. We are going to check the dist. cap, rotor, spark plugs and wires and also look for leaks with the boost controller. Any other ideas. These seems beyond the CHANGE the igition equipment like everyone else says. SO PLEASE HELP!!! THANKS in advance.
 

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A misfire puts extra O2 in the exhuast which causes the A/F meter to read lean.

The O2 sensor signal should never go away. Your problem sounds like bad wiring connection or a dying O2 sensor.
 

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boost said:
Ok first off I know I know, air fuel gauges tell you nothing, .
Hold on there! When I have a boost leak, my a/f lights stays in the rich for way too long after shifting. If your 02 doesnt bounce while cruising you may have a lazy 02 sensor.

Speeking of a/f gauges, I think mine just started malfunctioning. Its only been since 2001 and 100k since I had it. :angel:

Im going to swap it out with a good one to see if its my car or the gauge. My car has 221k miles on it now so I could be having any type of problem.

To reply to your question though, sometimes the lights will go all the way out when decelerating and start to bounce again after I stop.
 

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boost said:
But alot of the time the signal goes away and the car seems to be robbed of power. .
Your "A/F gauge" simply monitors the output from the O2 sensor. If it goes off intermittantly, you either have a failing O2 sensor, or a bad wirng connection (that's my first guess).

bill
 

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Discussion Starter · #5 ·
billwot said:
Your "A/F gauge" simply monitors the output from the O2 sensor. If it goes off intermittantly, you either have a failing O2 sensor, or a bad wirng connection (that's my first guess).

bill
Ok he is going to check that, but would that also cause the horrible studder or misfire problem I am having? It sounds internal though, and my mechanic said the same also.
 

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If the wiring connection is rusted out or bad then.. YES it can cause misfiring and or power problems. Cause the O2 sensor readings are not jiving with what the ECU wants to see. Check that wioring connection first. Then check that O2 sensor. Also, if O2 sensor is going bad your gas milage will usually be real bad too. Helped a friend install his A/F gauge and he spliced the wires in front of the plug (i.e. between the O2 sensor and plug) instead of, on the other side of the plug (wiring harness side per the instructions). For some reason his car would do the same thing you are desribing. We spliced the wire into the wires on the correct side of the plug and then the engine ran fine. Not sure why this happened but it did. So, check that wiring connection first. HTH

Daniel
 

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damn, i'm really glad i caught this thread! I'm in the same situation as well.

Everytime I step on the gas, my car is filthy rich. and when i left off the gas, there's no reading. I was thinking that my o2 sensor was shot and know that I caught this thread, I'm for certain that it's shot.
 

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Discussion Starter · #9 ·
ok, so pretty much forget the af reading because it is were I hooked the gauge up. I spliced into the wire in the middle between the o2 sensor and the plug. But the car is still running horrible. It sounds like it is the exhaust leak but my mechanic says it is a mechanical noise. He says the noise is so loud that it is telling the knock sensor to put it in safe mode and make the car run badly. Would the crack in the exhaust manifold make the car run this badly? It misfires, backfires, and it won't boost. The mechanic is going to take off the turbo and close off the fuel line and start the car to see if it has anything to do with the turbo. PLEASE HELP!!!!
 

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Discussion Starter · #10 ·
ANYBODY???

boost said:
ok, so pretty much forget the af reading because it is were I hooked the gauge up. I spliced into the wire in the middle between the o2 sensor and the plug. But the car is still running horrible. It sounds like it is the exhaust leak but my mechanic says it is a mechanical noise. He says the noise is so loud that it is telling the knock sensor to put it in safe mode and make the car run badly. Would the crack in the exhaust manifold make the car run this badly? It misfires, backfires, and it won't boost. The mechanic is going to take off the turbo and close off the fuel line and start the car to see if it has anything to do with the turbo. PLEASE HELP!!!!
 
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