Failed Emissions

[USAFPILOT]

Car is 1994 Model stock except for SW Headers HF cats and B&B cat back. The chip is still the stock chip. It passed all tests except high speed Nox (ppm) which has a standard of 821 and the car registered 918. The low speed test it passed, standard was 907 and it registered an 859.

I have heard about some tricks to get under the limit such as gas additives etc. I am in need of recommendations. I have never had the car dyne tuned since changing the exhaust. Would that be worth a drive out to Corey Henderson's to have it tuned?

What is it going to take to get in under the 821. What are the chances the guy was in the wrong gear?

[sammy]

best thing to do is call corey on monday. he wont try to sell you something you dont need . but i would be willing to bet he could get you another 15 rwhp and maybe more by dyno tuning . he does an awesome job . he even tuned my highway cruising fuel mixture . i got 23.2 on the 150o mile trip out to see him and 26.7 on the way back . . ask rick about what i gained when he tuned my 92 after putting headers on .

[RHanselman]

Originally Posted by sammy

best thing to do is call corey on monday. he wont try to sell you something you dont need . but i would be willing to bet he could get you another 15 rwhp and maybe more by dyno tuning . he does an awesome job . he even tuned my highway cruising fuel mixture . i got 23.2 on the 150o mile trip out to see him and 26.7 on the way back . . ask rick about what i gained when he tuned my 92 after putting headers on .

A tune goes a long way. I bought a 93 on the east coast and drove her to BG a few years ago. She was getting 23 mpg on the way there. Mark Haibeck did a dyno tune for me while at BG and she picked up 13 rwhp. The most impressive thing to me was she picked up another 3-5 mpg on the way home to Vegas. The first few tanks were 26 and the last few were 28...

I'm not sure about NV testing standards but all of my ZR-1's have never failed or come close... The turbo car has even passed with no problems with high flow RT's...

The new ECM's I working on will have the ability to have an emissions tune you can either load via your laptop or load via your power switch. I just don't know what results we'll get until we do some testing.

As far as tricks to pass they're a bunch of WOM's out there and I have no idea if any of these home remedies will work.

[rhipsher]

Really. I'm kinda shocked by this. The last time I was at your old house we installed the FIC injectors and it seemed to run fine. I just pulled my emissions testing out of the glove box. My low speed NOx was 306. And the high speed was 248. At 918 Ryan something is definitely not right. Does it run good? Is there any funny odor?

[USAFPILOT]

it looks clean but not I guess...I am wondering if I have something going on other than not having factory cats on it. It does back fire in between shifts if I am on it hard, but wouldn't that be happening if it is rich? Everything I am reading says high Nox is due to a lean condition, which could be true due to increased airflow? I am stumped. I hate to just throw money at it.

[USAFPILOT]

If my car was a 90 I guess it would pass. My previous score was 380 at 25mph with factory manifolds and cats. My HC's came up from 7 - 60 but well under the 117 allowed. Everything else is about the same. The only thing out of whack is the Nox jumping way way up from 380-918 at 25mph and from 417-859 at 15mph.

[rhipsher]

Mine runs lean also. I can see it on my last dyno sheet that corey did. Corey even told me it was running lean due to the fact its been top end ported and still running stock cats and manifolds. Im sure thats going to change once the headers HF cats and B&B are installed. Of course it will definitely need a tune after all of that.

[rhipsher]

Don't feel bad Ryan. I may be getting ready to go through the same thing.

[USAFPILOT]

i might need a passenger for the ride out to Corey's...I emailed him to get his thoughts on the matter.

[Z51JEFF]

I just went through this in Jan.Theres a few things you can do but your so close to passing it wont take much.One of the things I did the last time it passed was 5 gallons of E85 and 5 gallons of 93 octane.Not sure exactly what helped it pass because in addition to all the crap I tried I also installed new 02 sensors.Good luck.