rmac1100

Hi there! I recently bought a 1995 truck with a 305 that had new exhaust put on where they took off the cat and replaced with a straight pipe with a single inlet into the flowmaster and out duals to the tail pipe. They did a real nice job but I notice the pipes are pretty hot. The truck runs great but I dont know if taking off the cats requires the fuel mixture to be changed which I belive is controled by the computer. I checked the timing at it is right on so does anyone know what controls the fuel mixture? I dont want to burn up a piston or something if its running too lean.
Thanks,

oldchevy

Did they remove the 02 sensors? The exhaust pipes normally do get pretty hot.

rmac1100

The O2 sensors are still there.

kevinkpk

I believe the o2 sensors in front of the cat are used for fuel scheduling, so don't think it will have an effect.

Mudd Mutt

Yes the cats being off wouldn't have anything to do with the fuel mixture. You can burn your valves by not having them on but if you have muffler then your fine. Is your truck running rough or are you just assuming its running lean because of the cats being off?

zraddy

I got a 1995 with a 350 and just did pretty much the same thing with my exhaust, o2 sensor is off should i be wourried

rmac1100

It runs good just wanted to make sure nothing was necessary to adjust the fuel map is all. Thanks for all your thoughts.

Mudd Mutt

The pre cat ones are still gonna work the same way with no cats. The post cat O2 sensors just sense heat and tell you if your cat is working properly or not. If you've had a shop delete the post cat O2 sensors then your fine. If not there just gonna throw a code and your check engine light will be on but it will still run fine

Danny Cook

i have an 1985 camaro z28 that had a 305 5.0l q -jet carb that had a cpu that controlled something in the carb ignition and torque converter lock in, i later found out it had an aluminum crank in it that broke in half at the oil journals after 30,000 normal condition miles i had to scrap the block so i took out the cpu got an vacuum advance distributor and a tci vacuum torque converter lock out found another 305 had it hot tanked and red dye tested had the shop bored it 30 over put in steel crank flat top pistons and stock heads and rods tested, stepped up the cam a bit over stock its a lunati i dont know the lobe i just told the guy i wanted good power but good economy and dropped an edelbrock aluminum intake and edelbrock 650 4bbl performer series carb on it, my timing is set at 0 ''on the money'' as they say and i have tried to ''tweak'' the carb screws every witch way i can from stock to all the way in to out and it just dont have the throttle response or ''peep'' as the old stock 305,and it should have more after boring and bigger cam and carb if i punch it at a dead stop it won't even burn it does anyone have any suggestions how i can get a better response but not guzzling my gas maybe advancing the timing or a good carb setting would help out i would appreciate it greatly