Shane510

My 93 FD won't pass California emissions test. Does anyone have any idea why I would not be passing? (nevermind the visual) The emissions at 2500 rpms are nearly zero but the HC's at idle are still high. I just bought the car so I'm not too familiar with what all has been done to it. Rick at Rick's Rotary Performance has told me that I need to replace the underdrive pulley, but it looks stock to me. Could an after market pulley be causing it to fail? I'm thinking it's the M2 ECU.

I will list the modifications:
-6k on a rebuilt motor with new 99-spec turbos
-M2 ECU
-k&n high flow air filters
-cold box air intake
-power extreme intercooler
-koyo all aluminum radiator
-3 inch down pipe
-full flow cat


Thank you.

sevensix

iTrader: (1)

oh hc is only high at idle. didn't notice that in your PM. hope you get it figured out. i think some of my points will still work, gl

RLaoFD

iTrader: (6)

what do you mean by a full flow cat? putting in a regular cat might help you pass. have you also tried giving the car a tune up, replace plugs, change fuel filter, etc?

smog-guy707

iTrader: (11)

the intercooler are only making HC's worse... get a stock one and do plugs wires... how high are they?

sevensix

iTrader: (1)

how does the intercooler effect anything at idle?

Shane510

I didn't think the intercooler affected the HC's either. I replaced the plugs and it still didn't pass. It was 300 passing is 100

Shane510

Here's a picture of the pulley, is that stock?

RLaoFD

iTrader: (6)

I see no picture.

WaLieN

Untrue, such is the reason why ICs are exempt.

What is true is that an under driven accessory, especially the air pump, may cause you to fail in conjunction with a non-stock cat. Face it: albeit the stock cat is somewhat restrictive (due mainly to poor welds), you will be hard pressed to find a replacement cat that will catalyze exhaust gases better than an OE unit.

Furthermore, the air pump is really finicky, especially with old age. When doing a CA smog test, the tester failed several times because couldn't keep the cat within the range where the clutch is still engaged. As a result, it took multiple tries before he was able to get the car to pass.

adam c

iTrader: (2)

The M2 ecu is a stock ecu. It only changes your fuel maps upon hard acceleration. The ecu is not your problem.

I suggest increasing your idle speed to around 950. This should create a "hotter" cat, which should burn cleaner.

ThoRx7

-6k on a rebuilt motor with new 99-spec turbos
-M2 ECU
-k&n high flow air filters
-cold box air intake
-power extreme intercooler
-koyo all aluminum radiator
-3 inch down pipe
-full flow cat

i think it could be the rebuilt... because since its new the timing might be slightly different especially with the 99spec turbos... and the ECU if thats changed it could cause the emission to change also due to if it was built to race so i think u'll have to find a stock one... k&n filters are fine... cold box fine... intercooler should be okay but at the same time the intercoolers recieving more air though.. but i think it should be okay.... radiators fine because its just help for the cooling system... 3 inch down pipe another problem because its leting more air out to not pass cali emission so i dont think it'll meet the requirements.. the cat should be fine tho... if your just talking about the cat-back that is...

axnjaksn

iTrader: (2)

HC'S are hydrocarbon's, aka unburned fuel, so one way or another your car is running rich at idle, not sure how esle to fix that without recommending a new cat, or puttin a gallon of de-natured alcohol in the tank with at least a half a tank of gas, get the car nice and hot before you take it to the smog station and do not for any reason turn off the car, leave it running to keep your cat hot!!!

Shane510

Is this a stock underdrive pulley?

darkside7

iTrader: (12)

are you sure your air pump is working?

Shane510

I think so, how can I check it?

axnjaksn

iTrader: (2)

besides that your air pump should only be on at idle when the engine is cold

Gadd

No, that's a Pettit underdrive pulley. It would cause the air pump to run slower at idle and not pump the necessary air to dilute the exhaust. Rick knows his stuff, I'd trust his judgment.

The pump runs from idle to about 3000 rpm cold or warm

Shane510

Gadd, thank you! That's what I thought, and that's exactly what he told me. It makes sense. He said the intake and intercooler aren't affecting anything except visual which I don't need to worry about. I just thought the M2 ECU may be affecting idle.

It looks like I will be switching that pulley out with a stock one. Has anyone ever done this? Is it a bitch? I heard there's a bolt that can fall back inside the motor and I need to keep the clutch pushed in while switching out the pulleys. Any advice would be helpful, thank you.

BADSVN2000

you shold be able to just unbolt the pulley and bolt the stock one on no probs, dont undo to main bolt on the eccentric shaft, just the 4 10mm bolts oh and the pully can only go on one way so there isnt really anything you can **** up.

Shane510

Thanks, that helps. I just don't want to screw anything up. I'm not much a mechanic but I like to learning as much as I can.

FDeez

I don't know about that. I've passed with that exact same pulley before and a high flow cat in addition to your mods. Trying running some seafoam in your car to clean out the engine and the cat. Warm up the car and cat, then take it for smog check.

grimple1

iTrader: (1)

i'm kinda suprised it'd fail b/c of underdrive pulley. keep us posted on your progress...

Shane510

Got that additive from Kragen that is supposed to make you pass, replaced plugs and ran it on the freeway and kept it in high RPMs all the way the to the smog shop and didn't shut the car off. It was nice and hot and it still failed. So far I am looking at replacing the main pulley and switching in a stock computer and a couple gallons of high octane race fuel.

wstrohm

I nearly went mad trying to get our almost stock '94 to pass, back in 2000. The only thing that finally worked was buying a new OEM cat. A new Bonez cat failed, plugs/wires/Techron/tuning did not help.

Shane510

I have my stock cat, that's the last thing on my to do list.