Need help BAD!!!!!

Two things, first of all I just put in some DCSports Headers, and I drove it home from my uncles shop and it was fine, but when I stated it up, for the first time after and let it idle for a couple of min the check engine light came on. Does this have anything to do with the Headers or just coincidence and it is probably something else?????
Also I put in new Bembo Rotors and pads and I put the tires back on when the car was on the lift but there is a knocking sound that hits once wheel rotation(only on rear wheels), and a slight grinding sound. Is the wheel unbalanced cause I put it on while the car was in the air or something else?????? PLease help

did you accidentally unplug the o2 sensor when you installed the new header? that could throw a CEL.

aanndd..

did you tighten down the lugnuts and torque them to 100 lbs/ft?? make sure the wheels are all torqued down in a star pattern to ensure proper tightening.

I did put the o2 sensor back in the new headers, and it was fine when I drove it home???? And I did tighten the lugs in a star pattern but I didn't torque them cause I was using an air wrench, so could it be too tight?????

using an air wrench on lugnuts to tighten them is probably one of the worst things you can do because they all go on at different tightnesses. i would run a CEL test and see what you get for codes.

and it was fine when I drove it home????


Before the ECU throws a CEL you have to satisfy certain conditions.

Example, car must be up to operating tempatures, fans must cycle 2x and car must be driven over 50mph for 2 minutes, etc. I just made those conditions up, but you get the point :wink:

Anyway, it probably took you the drive home to satisfy the conditions.

Get the codes pulled at Autozone, they do it for free.

ok I found out that we actually owned a code reader OBDII, Sweet. I used it and it popped up the code PO134, When I looked it up, it said "o2 sensor circuit activity not detected(Bank1 sensor1)"
Which I am asuming means the header sensor but we did plug the sensor that was in the stock headers into the new headers in the new spot??? Does anyone know what I can do to fix the code and or if that is what the code is for???

You probably did not connect it correctly. Make sure it's not backwards/upsidedown/loosely plugged in. It should be threaded all the way into the new headers. You could have damaged the sensor when removing it from your old headers, and it may no longer work.

It's probably a good idea to get that fixed soon.

If the sensor got banged around or even just taking it off it could have broken the ceremic internals, as for the tires you could have bent the rims. take em off and put em on and torque the to specs.