Running Rich and Backfiring?

Synchros shot? Weird noises while shifting? Not sure what needs to be replaced?
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Warner
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Running Rich and Backfiring?

Post by Warner »

Over the past couple months I've noticed my car's exhaust smells pretty strongly like gasoline. Also, maybe a few times per month my car will noticeably backfire while I'm accelerating (I hear a pop around the area of my exhaust manifold under my car and there is a sudden but short-lived loss of power). There is no check engine light or anything like that.

So I guess that means my car is running rich. Is this a sign that my o2 sensor is starting to go bad or something else?
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theholycow
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Re: Running Rich and Backfiring?

Post by theholycow »

Check forums for your car, there may be a procedure to pull the OBD-I codes without a tool. If it requires a tool, the tool may be cheap. You may have codes even without a CEL.
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kamesama980
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Re: Running Rich and Backfiring?

Post by kamesama980 »

94 geo prizm...aka toyota corolla. yes you can pull the codes without a scanner. find the diagnostics connector in the engine bay. it'll be near the top probably near one of the strut towers or intake manifold. it'll have 15 or 20 terminals in it and look like a plug into nothing with a cover over it. use a paper clip or bit of wire to short pins Te1 to E1 then go inside the car, turn the key to 'on' without starting the engine and count engine light flashes and pauses. write them all down till it repeats the whole thing.

you can see the one on my old cressida here between the end of the fuse box and the grey block on the strut tower.
http://s29.photobucket.com/albums/c265/ ... CF0637.jpg

TCCS won't set/store a code without setting a CEL (Toyotas OBD1) You'll still have to pick up a manual to find out what the codes are, I don't have a reference sheet for the corolla and I've checked on them in the past without luck short of buying the manual or really looking hard.

backfiring under hard accel and/or actual fuel smell from the car sounds like a lot more than a bad O2 sensor. more like a dead or intermittent cylinder.
-Russ
2012 Nissan Frontier 4.0l M6 4x4
1990 Toyota Cressida 3.0l M5
1994 Pontiac Firebird LT1 M6
1970 Volkwagen Beetle M4
1990 Suzuki VX800 SM5
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