aircooler

Today I found out why my S4 had failed its emissions test.

Last Novembers failed emission test thread

I was having a garage install a new O2 sensor when the very astute wrench tapped my cats, listened and said "They are empty".

Well sure enough, we pulled the back of the exhaust off the car, and not only were they emptied out, but there was a pipe welded inside each of them so as to make them strait pipes. The exterior of the cats were for looks only!

**** !!!

Anyone have a spare cat assembly (MY 87-88 only)?

This is my second 10-day permit, and still no plates.

NO SOUP FOR ME!
Mike

Jim bailey - 928 International

Did that car once live in Ohio ? does it idle a bit rough ?? with RMB and straight pipes it must roar !! If it were running right it should pass smog with no cats .......

aircooler

Jim,

It's a Canuck car, runs smooth, and yes, it announces its presence!

I am intrigued by your response.

If it were running right it should pass smog with no cats

I didn't get the O2 sensor installed because I thought it to be a waste of time. Jim do you think that I should get it in and try a retest?

!!!!!STRAIT PIPES!!!!

40 km/h_____LIMIT_____READING_____RESULT
--------------------------------------------------------------
HC ppm_____65________216_________FAIL
CO %_______0.36______1.33_________FAIL
NO ppm_____0726______2126________FAIL
RPM__________________1352________VALID
Dilution_______________13.33________VALID


CURB IDLE___LIMIT_____READING_____RESULT
--------------------------------------------------------------
HC ppm_____200_______168_________PASS
CO %_______1_________1.11________FAIL
NO ppm_____N/A_______N/A_________N/A
RPM__________________764_________VALID
Dilution_______________12.70________VALID

Cheers,
Mike

bcdavis

I bet you will have no problem finding someone to swap cats with you...

Jim bailey - 928 International

with out the 0 2 sensor the engine computer defaults to rich too much fuel and it would have high HC .

Barry Johnson

Are the emissions tests more stringent than in Washington state? The last time I tested on the dyno tester, it passed and my S4 had gutted cats. Try getting the engine up in the revs on the freeway for a bit and then taking the test again.

BrianG

You need the O2 sensor for the lambda circuit to function and properly adjust the mixture. Without any number of the sensors (O2 included) the computer drops into "limp-home" mode which is very rich, but safe for the engine. As Jim says.......... that'll blow the sniffer test!!

rsneek928

Mike,

I don't have a spare set, but if it is not too much trouble to do, you could have use of my exhaust for a day so you could pass the emissions test and then throw your set up back on.

I have to take mine in for drive clean and safety (changing insurance co's) next week, but am waiting for new brakes from 928 int'l before i do this. Car has been off the road for two years but passed drive clean easily last time.

I'm in Stouffville about an hour or so from you. Let me know if this would help and we'll try and make arangements. You would have to come to me as car is not legal to drive at the moment (no tags). Or can you wait till I have the car on the road late next week or early the following week.

heinrich

I have a spare ....

ROG100

Mike,
I am still suffering similar problems.
However I did find a number of aftermarket cats (Brand new and look identical to the original) available for $350 delivered.
Fit the cats for the test and then remove for the rest of the year.
I can PM cat details if you want.
Best,
Roger

ViribusUnits

I dought it'll get you into the PASS region.

Even if you have an O2 sensor, and good cats. It might just get you by, but...

Your way up high on everything, which should not happen. Eighter you should be high on the CO and HCs (rich mixture) or high on the NO (lean mixture.)

To me it sounds like the fuel mixture in each of the cylinders isn't the same. Some seem to be running a little lean, and makeing way too much NO, some a bit rich, and pumping the CO and HCs out. This is incidently EXACTLY what I'm fighting in my car. One or more of th injectors are leaking, and each cylinder is getting a diffrent air/fuel mix, and it's confuseing the ECU in closed loop opperation.

However, fuctional cats and an O2 sensor can't hurt!

aircooler

Well I got the new O2 sensor in and still NO SOUP! Not even close.

The car still failed miserably but did improve somewhat in CO%.

STRAIT PIPES / NEW O2 Sensor

40 km/h_____LIMIT_____READING_____RESULT
--------------------------------------------------------------
HC ppm_____65________216 / 219 _________FAIL / FAIL AGAIN
CO %_______0.36______1.33 / 0.83 _________FAIL / FAIL AGAIN
NO ppm_____0726______2126 / 2186 ________FAIL / FAIL AGAIN
RPM__________________1352 / 1265 ________VALID / VALID
Dilution_______________13.33 / 12.9 ________VALID / VALID


CURB IDLE___LIMIT_____READING_____RESULT
--------------------------------------------------------------
HC ppm_____200_______168 / 155 _________PASS / PASS
CO %_______1_________1.11 / 0.59________FAIL / PASS
NO ppm_____N/A_______N/A_________N/A
RPM__________________764 / 723_________VALID / VALID
Dilution_______________12.70 / 12.3________VALID / VALID

Looks like I may be fighting other demons. I will go and replace the cat anyway, then try another re-test. At least then I can eliminate exhaust. If it fails again with a good cat, I will take the car to Henry at "Refined" in Toronto and have him put his tuning fork on it.

Rob, Thanks for the kind offer. However I want this car running "just so" so I will get a cat assy to permanently install. I may need it on the car for a while if I have to chase down other related problems, and unfortunately my time is at a premium right now so that may take a few weeks. We should meet up one of these days! I'll PM you.

Roger, thanks for the heads up. I may look into AM cats. Hope you have better luck than I am having!

VB, you may be right. I will get the cats on for now, and then see what develops.

Thanks for you input guys,
Mike

Earl Gillstrom

Mike,

A few things to remember: Cats are designed to do a final clean of a "clean" engine.

A "dirty" engine will destroy a cat. So, if the new cat does not solve the problem, get the dirty engine fixed ASAP, before you destroy the cat.

Garth S

Hey Mike,
Reading your latest episode, I'll reitterate the comment in the PM sent ( if you received it) .
Since there was effectively no change in the second test, it is even more possible that the PO inserted the tubes far enough into the CAT to effectively close off the X-over pipe that houses the O2 sensor well. Were that the case, the orriginal sensor may be OK (don't toss just yet) - just reading stale air, cobwebs, ... Easy to test, just back off the sensor and fire up! Who knows what happens when 'professional wrenches' begin to modify things?

Thaddeus

Have you tried running injector cleaner through? Sorry if it's so obvious and dumb, but... if yu haven't then it sure can't hurt...