Emissions testing after engine mods

[dr.porsche]

Has anyone had trouble complying with emissions testing after adding a bigger cam or headers to their truck?

Thanks

Jeff

[vhato]

My neighbor has an 02 Camaro SS with a Cam and Long Tube Headers. The stock O2's are all over the place so he had to put in O2 simulators, so I would say yes, a Cam and Headers may cause you to fail.

 

If you are from a state that only checks the OBD2 data then you would pass with the O2 sims. However if they stick a wideband sensor in you exhaust pipe...flunk city.

[hercman]

If you use parts with a CARB approval number you should be fine. Headers don't in all reality affect emissions. The grind of the cam could. If a state does a sniff test you can always take it in and have a prelim test done before the actual emissions test to start with. Be sure to keep the mouth shut as to which parts your vehicle has otherwise the testing station could ask for the CARB numbers for those parts and even if you pass and you don't have CARB approved parts then you'll fail anyways.