emission question!?

Hi my name is cam and i live in denver... and i happen to the live in an area that does emission testing! i recently bought my first galant vr4 975/2000 and i took it in for the test and failed with the readings of...... HC GPM LIMIT:1.5000 READINGS:1.0418, CO GPM LIMIT:20.0000 READING 40.2977, NOx GPM LIMIT:3.5000 READINGS:0.6749

In my understanding it is running rich... i have an evo8 front mount& hard piping, tail bov, 3" MAF with MAF translator, and DSM link other than that it is all stock even the turbo.
i was told to put a couple gallons of e85 that will lean it out but will it lean it out enough?! i also was thinking about putting a stock ecu back in it along with the e85, or should i leave the link in it and lean it out on that along with the e85?

if you guys could give me your input/hints/trix would be great!

THANKS.
CAM

 

[Andy_S]

Put a good universal (cheap) cat on. Just that will help a bunch. E85 helps, but in my experience it didn't do enough and the nox shot up. Keep link in and tune it better.

 

If you have link there is all kind of stuff you can do to "pass" emissions. Simple tuning would be number one, but if that doesnt work....

Turn down the boost
try leaning it out a bit more
You can disable one injector in dsm link..... wont run very well but you may pass

A cat is not a bad idea either.

 

[toybreaker]

Quote:

Turn down the boost
try leaning it out a bit more



^^^ good advice

Quote:


You can disable one injector in dsm link..... wont run very well but you may pass




^^^ This, not so much.

Disabling a hole by turning off an injector will raise the c.o.. exponentially.

Without fuel, that cylinder will pass the air straight into the exhaust stream.

The oxygem in that hole's share of the airflow won't be a part of a combustion proccess and will pass straight into the exhaust stream. The o2 sensor will see the excess oxygen in the exhaust stream, (becuase that cylinder is just passing the air thru.)

... and the ecu will toss a buncha fuel trim at it to try and hit stioch (ish)

In addition, the im240 test protocall isn't a percentage of exhaust gas like in days of old...

... it's grams per mile ...

So not only are you putting out more c.o., a dead hole will require more throttle, and more schmeg will go out the tailpipe from the operating cylinders.

Quote:

A cat is not a bad idea either.



^^^ Back on track /ubbthreads/images/graemlins/smile.gif

If there is a cat present, check it's operating efficiency with a digital pyrometer.

If there isn't a cat installed, hang one and make sure to get it good and hot on the way over to the testing station. Keep the engine at a fast idle (1100 rpmish) while waiting in line do NOT shut the engine off untill you have to.

This will ensure the cat is hot and ready to rock.

A 4g63t in good running condition will almost pass without a cat, but if the dyno monkey has to throttle it up more than necessary on the rollers to follow the load curve, he'll force it into open loop, and at that point, all bets are off and it's up to the cat to clean up the extra fuel.

If the motor is running well, it'll take less throttle to achieve the same road speed, and that's a win all the way around.


You have ten days for your free re-test. I would suggest you take your time and fully sort any running issues you may have, and then try again.

If you can, scan your dyno plot.

It's on the back of the print out you recieved when they took your money and gave you the bad news. The trace of load to particulates will tell many tales, and will help us troubleshoot this problem with you.

 

thanks for all of your guys info!! hopefully this will get it to pass.... but we will see