Failed emissions
 

94 zr1 with haibeck top end work. Headers, no cats.

Passed everything except the hc at idle. Allowable limit is 220. Tested 3 times, read 561, 260, and 461.

Car sat for two years, I think I've run most of the bad gas through it, currently on second tank of fresh gas, added fuel system cleaner to both fill ups. Only issue with the way it runs is an off-idle stumble.

Ideas?

Thanks,
Jack

Re: Failed emissions
 

move to another state

Re: Failed emissions
 

probably a tune someone could do for the test

Re: Failed emissions
 

Injectors going bad?

Re: Failed emissions
 

put cats on it

Re: Failed emissions
 

Well, yeah, putting the cats back on is the obvious solution, but I've seen posts where they've passed without them. And it's fine at higher rpms. I'm thinking its related to letting the car sit. The way it acts from zero throttle to a little bit open, if it was carburator, I'd look at the accelerator pump. I don't know what the equivalent to that is with fuel injection. Was hoping to hear from someone very familiar with the fueling systems and what might be causing it to run rich just at idle. The car has only 19,000 miles, new plugs were put in about 2,000 miles ago. I hate to go the effort and expense replacing the injectors and then discover it doesn't run any differently. The secondaries are wired open, if that makes any difference.

Re: Failed emissions
 

The tune is adding fuel and timing which will raise emissions, but you could still pass if you had the oem cats. Not having cats with a chip...you don't have a prayer. At least put a stock chip in it.

Re: Failed emissions
 

I'm expecting my registration renewal in the mailbox any week now. My car passes normally, but I'm curious to see if I cheat like VW to lower the NOx, how much it will help.

Re: Failed emissions
 

Replace cats

Re: Failed emissions
 

No CATS = no PASS