I've had my long tubes and ory-pipe on my truck for a while. Since i took my cats off my fuel mileage has decreased. I do have a Nelson tune and it was suppose to fix the issue. Is there any way or tricks to get my fuel mileage back to the way it was with cats? I am still throwing codes also! Thanks

 

what codes is it throwing? if it is for the rear o2's then the tune is not right.

 

im with ya saame here !i cant get my a/f right for nothing same tune .but i do have true duals .delete cats and o2s .but icant stoppopping po141.ive even replaced my inake gaskets cause factory say that was commin for po 171 and my gas mileage is terrible.im tired of screwing with it.ive had like 5 retunes.idk what the deal is but it sucks i cant even beat the **** out of my truck without worrying about blowing something.f/i ya know.

 

u can buy o2 simlators they help

 

the codes are P0054, P0060, and P0442. These codes are recieved from my interceptor scan gauge.

 

54 and 60 are rear O2 codes, looks like he forgot to set them to "no error reported". As for the 442 it's an EVAP small leak detected problem.

just a quick question, do you have the rear O2's plugged in at all?

 

what about my stupid po171?i cant seem to figure out after exhausting all thoughts

 

hmmm, fuel trim system lean bank 1. I'd take a look at your tune. do you have any logs/tune files you could post for us to look at?

 

o ive got plenty of logs ,i will tomm id appreciate it.it doesnt go lean like its supposed too when no throttle slowing down .it if anything goes rich .

 

that's odd