Hey guys

Heres the story. i have a 91 z28 camaro, 305 tpi and i just finished installing heddman hedders 68470 and the matching y pipe. i welded a bolt for an o2 sensor on the collector of the drivers hedder and installed it. im running open y for now until i can put in the cat and connect the rest of my 3 inch cat back. now the problem is this, i deleted the a.i.r system and left the smog pump in there. when i test drove it, it ran pretty smooth but it seems to be hesitant and i believe it misfires a tad because it will have a rough acceleration. my spark plug wires are rather old and i believe that could be the problem.

please help

 

Check your wires for being in their proper places, being burned and snapped on tight. Are you running an O2 sensor at the moment? How it reads to me is you put a bolt in place of it. Your car needs an O2 sensor to run properly. Unless you meant you welded a nut on the collector for an O2 sensor to screw into.

 

If you are runnin g an 02 sensor, you may have exhaust diluition (regular air) getting in the exhaust stream, screwing you the A/F ratio

 

Shouldn't be happening with the y-pipe on unless the O2 is right at the end of it.

 

since the rest of the exhaust isnt on there. and you are running headers on top of that the 02 sensor is not heating up enough with all the airflow.

 

sorry i meant to say i do have an o2 sensor screwed into the nut. the screw right at the collector of the driver side hedder.

 

Oh I bet it is getting hot enough.

 

actually if it is still a one wire it is not getting hot enough quick enough. and it is allowed to cool off. if you were to put the rest of the exhaust on or a heated 02 it would help out. i suppose some dont have problems and some do. when i did my headers and exhaust i would get the 02 code once in a while and it drove me nuts. put in a heated 02 and the light never came back on. and better mileage to boot.

 

turns out, i found a broken spark plug on one of the cylinders. how this happened im unsure. but i appreciate all of your help!

 

You may have bumped it installing the headers or it cracked removing/installing the plug. Glad ya found the problem anyway.