bianchi

had to replace my starter at work this morning ( i am a nissan sales person )starter went in easy.but had to drop the downpipe ,as i droped the down pipe that little metal?dounut slip out and fell a hole 7 inches to the ground and broke,well could not get a new one,so just bolted it up togeather as best i could. a little gap betwean the down pipe and the cat.under acc. it makes a LOT of noise, but once i got up to crusing speed 75 mph and let of the gas very quite. my gas milage jumped 3-4 mpg. nice!!! a question. how can i make an exhaust system that will be not to louad uder acc.and quite at speed? any help here 1989 100 non- turbo car. thanks randell

Pete S4

Normally I don't think something like that would increase gas milage. Especially to that extent. However, as a wild guess, could your cat be clogged up? That I might buy as having an effect on gas milage.

5000CDQturbo

With not so much back pressure It would make sence to have better gas mileage. As the warmer weather is now here, you will notice better gas mileage.