ETR

My catalytic converter went bad on my 1992 f-250 supercab, auto trans, 2 wheel drive. I live in a very, very small town in North Texas and when I took my truck to replace the catalytic converter, the muffler shop did not have one on stock and when he called to check for prices he was told "after markets" cost from $700 to $1,100. Long story short he told me "lets just cut it off and put a straight pipe and leave the converter off". By the way he checked it to see if it would pass smog and it did. His shop is also a Texas smog inspection station The check enging light did not even go on. BUT, now my gas mileage went down to aprox 5 to 6 miles a gallon from what I was getting, aprox 10 to 11 miles a gallon. My question is, is this what effected my gas mileage, by removing the Cat or do I need to retime the eng?? With prices of gas today I can not effort to drive this truck. I would like to hear the forums input in this subject. Thank you in advance......Ed

 

amarthfea

I can think of two possibilities of why fuel economy could go down with the removal of a cat. converter.

1. your old cat. converter may have had a pre or post cat. converter o2 sensor in it, and that sensor hasn't been reinstalled. causing your engine to not preform properly due to the lack of an o2 sensor.

2. without the cat. converter you may have another post cat. converter o2 sensor that is trying to correct the engine. since the cat. converter is gone its not reading correctly causing it to adjust the engine incorrectly, which may lead to poor fuel economy.

remember the function of the cat. converter is to try reduce the tail pipe emissions. the o2 sensors detects the amount of unburnt fuel (in short) and tries to adjust the engine so that is will have less unburnt fuel going through the exhaust system, causing less tailpipe emissions.

~adam

ps. is this in the right section?

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'52 Ford Meteor. It may be well rusted now, but give me 5 years.