I have a 96 Z71 that gets terrible gas mileage. Usually around 12.5 to 13.0mpg. It has a 350 engine and i have had other people tell me that they get like 16 or 17mpg. I read a post about putting on an electric fan and doing away with the engine fan. But what about the O2 sensors and the converters. The check engine light stays on and its something to do with catalyst efficiency usually. I'll check it again tomorrow with the scanner. any help or tips would be appreciated. this 400 bucks a month for fuel is really getting old. Jimmie

 

That's roughly what I'm getting on my 98 2500 with the same engine when running in 2wd without the plow on. Everything seems to be okay and I feel I should be getting slightly better economy. I'm thinking of cutting off the CATS and installing 02 dummies. maybe purchasing a chip??

 

Where can i get "02 dummys"?

 

I'll try and find the old thread where someone linked me to them and get back to ya

 

thanks

 

try a new distributer cap and also check the catalitic converter my son just sold his 99 tahoe with 289,000 miles and he was still getting 16-19 on the hwy pulling a tandem trailer with2 four wheelers and gear moose hunting,my old 95 gmc got 16-20,main thing is keep rpm under 1900

 

thanks for the reply i have already replaced the dist cap and button. I think there is a problem in the converters. The exhaust always smells real rich. I think the 02 sensors are telling the ECM to dump more fuel in the engine to get the converters up to operating temperature. Either their not getting to that temp or the rear 02 sensor has a problem. Am i shooting in the right direction? Maybe

 

the exhaust is plugging up the 350 should really get good milage ,up here in canada from sept. to april /may the vehicles are forever running with the chokes on due to temperatures but on the hwys aren,t to bad.we drive about 2400 miles over the great lakes near the manitoba border in oct the milage from the 99 tahoe and brother in laws toyota was only4-5.00 difference, other brother inlaw said for the difference in gas he would sooner pay it and not be crunched up in the toyota. you can also trythe chip that you install in computer they do work

 

ok so does anybody know where i can get some converters for a decent price. I know those things can get kinda pricey. Thats the only thing that i think can be clogged up because i had 300 bucks worth of flowmasters and pipe installed. however the converters are the original ones from the factory with 270,000miles on them. On the computer chip where can i get one that really works for a fair price