04 avalanche with long tubes and ORY. I have HPT. I moved to a state with emissions and I get a not ready failure for 3 parameters. I have a pretty good guess what I need to have the rear O2 DTC's set to, but dont want to go back to the shop 3 times to get it right. If someone could PM me I would really appreciate it. Does anyone know if the o2s not being ready will trip the evap and cats not ready also? I had enough gas and temp that the evap should have performed the cycle. Ths funny thing is my 98 blazer that I know runs dirtier than my avy sailed right through the scanner.

Thanks!

 

im in the same boat right now....went throu emissions last week and failed due to my cats sayin not ready....and evap not ready......deleted the codes prior to goin in and forgotit needed time to reset....tryin to find a solution too

 

I just failed my emissions test for the first time ever this week for the exact same thing...o2 not ready...evap not ready..o2 heater not ready....is this tune related???..I put very little miles on the truck and all driving is short trips.....could the mostly less than a few miles at a time cause the not ready??

 

anybody???

 

This type of post seems taboo here. Im waiting to get my hpt cable back. If there is a way to make it pass with just tuning Ill pm you guys how. I looked at my tune and I only had the light turned off which is probably why I got the not ready.

 

Could also be the time of year....the long tubes dissipate heat quicker than the stock manifolds....maybe the o2's are not getting hot enough to switch to ready.

 

search LS1 tech, there are many threads regarding this issue.

 

Thanks

 

It can be done with tuning. (for future searchers)

 

tuning that needs to be changed every inspection time?