Failed Emissions...NOx & HC...EGR Valve?

[91CRXTC]

Hey i just brought my car in for inspection and it failed. I got 1.06(0.80 Limit) and got 2.97(2.00 Limit). My CO was good @ 10.85(15.00 Limit), So heres this. I did an engine swap to a ZC less then a year ago, but havent gotten a tune up since. Should have done after engine was broken in. So the guy said it may be the EGR Valve, i looked it up and i do recognize some of the simtums of a bad EGR. So my Q is, How much work would it be to replace it myself? How much ya think it costs? Where is it located? And would doing this with a tune up help bring my NOx and HC down? I have a header and new cat on also, oh and if i went from a 2.5" cold air intake to a 3" cold air would that help also? Please help if you can, and if you can...THANX! *Jay

Oh! just foundout that a ZC motor doesnt have a EGR Valve, So im changing the plugs, and O2 sencer, Valve Adj., and check timing, I put in an MSD since the swap so it might need to be re-timed. Also gonna see if a 3" intake will help. IF any suggestions please let me know. THANX Again!

[rubix777]

what octane gas do you use? the higher you use, the cleaner it burns. so 91 octane actually pollutes less than 89

[91CRXTC]

I use 93Ultra (Sunoco) which is really 94 but they had to stop labling it that cuz other gas companies dont go that high.

[rubix777]

check your plugs
adjust timing
maybe some fuel injector cleaner

enlarging the intake, usually the computer controls the air, so that probably wouldn't make a difference.

[91CRXTC]

I thought the computer adds gas to the amount of air that the throttle body butterfly allows in. So in sence..you open the butterfly air comes in and the comp reads amount and adds gas to the mixture. My ass-umption.

[rubix777]

Originally Posted by 91CRXTC

I thought the computer adds gas to the amount of air that the throttle body butterfly allows in. So in sence..you open the butterfly air comes in and the comp reads amount and adds gas to the mixture. My ass-umption.

yeah you are right.