failed emissions this morning.

**EagleMark** · 03-18-2014

Maybe? That is what we want to rule out. But from what Fast is saying it's probably all the spark I have in your chip... or that and as Buzz mentioned a non efficient CAT. It's amazing how much a CAT can clean up and for the little bit of HP lost it's really just a good thing for the air!

**one92rs** · 03-19-2014

here is the log I did today. popo everywhere and 5 oclock traffic. got a good freeway run in there. and a couple small full throttles.

yeah but that chip runs very well. I like all that it does.

**Fast355** · 03-19-2014

Originally Posted by EagleMark

Maybe? That is what we want to rule out. But from what Fast is saying it's probably all the spark I have in your chip... or that and as Buzz mentioned a non efficient CAT. It's amazing how much a CAT can clean up and for the little bit of HP lost it's really just a good thing for the air!

Are you using your 14.1:1 stoichiometric trick in that chip? Also have you tried lowering the 02 voltage cross points about 10%. Leaner will reduce the HC/CO but increase the NOx. Leaner than 14.7:1 can also reduce the NOx by reducing combustion temps but go too far and it will pickup random misfires that will increase HC. Retarding the timing will further cut the HC and at the same time lower the NOx. How old is the 02 sensor? If it is a non-heated sensor GM once recomended to replace them every 30K. A sensor that is starting to fail will run the engine richer and richer, causing emissions to increase.

Changing the oil seems to help as well. You could also block off the PCV vacuum hose internally as that will help lower HC.

FWIW the california .bins were always richer with the timing more retarded and almost always had an air pump. The richer mixture and retarded timing decreased NOx and the air oxidized the HC and CO.

**one92rs** · 03-19-2014

I got this chip from EAGLEMARK. that 02 sensor is less than 2 years old and is the casper electronics heated 02 sensor kit. no air pump on her either. was going to change the oil right before going back to inspection. I can block off the pcv valve. the inspector is really cool. he wouldn't even care if the pcv wasn't on there. is there a way to retard the timing manually?

**Fast355** · 03-19-2014

Originally Posted by one92rs

I got this chip from EAGLEMARK. that 02 sensor is less than 2 years old and is the casper electronics heated 02 sensor kit. no air pump on her either. was going to change the oil right before going back to inspection. I can block off the pcv valve. the inspector is really cool. he wouldn't even care if the pcv wasn't on there. is there a way to retard the timing manually?

Yea by retarding the distributor. I do not know how much timing Mark added, but it could be substantial in relation to the stock TBI tunes I have seen. If I can pass with no cat, no egr running a 454 tbi and an edelbrock non heated dual plane intake you shouldn't have an issue getting a stock tbi engine to pass.

**Fast355** · 03-19-2014

Something else that sticks out is IIRC it was well documented in the older days that the lack of factory backpressure often prevented the factory positive backpressure EGR from opening and often a TBI truck negative gbackppressure egr was needed to keep code 32 from showing up. If you have a spare set of hands get the car up to operating temp and get someone to lightly powerbrake the car and bring the engine up against the converter a little. Feel the backside of the EGR to see if the diaghram pulses rapidly.

**EagleMark** · 03-19-2014

It is at 14:1 Stoich. The Air Diverter is coming on in data log... but your Ca car does not have one? Ooops! It does have a lot of spark compared to stock and just looked at this log and no knock counts.

Lance has this always idled hot? It was up to 210*f at the end of this data log. Fueling was where I always shoot for, little rich of 128. But when it hit 200-210*f the BLM went to 108 and I think that's bottom. MAT was at 125*f.You got the stock air cleaner on or the Open Element? So I'm wondering if it getting hot is causing the fail?

**one92rs** · 03-19-2014

I can set the fans to come on when I want them. flexalite controller. I can set them cooler. when we were tuning I had the open element air cleaner. I have to put the stocker on it when I do emissions. I have drilled a bunch of holes in the bottom to try to get as much air as possible. what can I do to help it out.

**EagleMark** · 03-19-2014

Get a base without holes so it sucks cold air! and get the fans on earlier so it does not get this hot.

I just don't know what to do with tune to help pass, waiting for tips?