EMISSIONS

SON240sx Automotive
1

Hallo guys! Need your help ASAP, I hope someone has seen something like that before. I have yr 93 240 with the ka-de, went to emission test yesterday, and here is what it shows:

ASM2525 TEST(when rolling 40 kph):
HC ppm: 80 (limit is 64)
CO% : 0.42 (limit is 0.35)
NO ppm: 1543 (!!!wtf) (limit is 485)

CURB IDLE TEST
HC ppm: 198 (limit is 200)
CO% : 0.36 (limit is 1.00)
NO ppm: NA NA

RPM 923
Dilution 15.0

Why is NO 1543, three times more than the limit? Perhaps someone did encounter situation like that, what would be the cause, and what do I fix?

2

id say your cats pooched, how long has it been on the car?

the no reading was like that on my old ford, changed the cat, passed.

3

Couldn’t that be egr problem as well? Cat definitely needs changing. It’s been on the car forever.

4

yes it can be an egr problem. mine was double the limit because of my egr. but i bypassed the BPT valve and it passed

5

What’s the BPT valve? How did you bypass?

6

the bpt valve monitors the exhaust pressure to activate a diaphragm that controls the EGR vacuum. im not to sure how we bypassed it. i had someone do it for me. maybe someone else on here knows what to do. but it will bring you HC up a little

7

The thing is that the exhaust gas return pipe cracked, and is now blocked.
How about if I partially block the exhaust pipe, leave a hole, say, only 1/2 inch in diameter, this as well should reduce the burning temperature in the cylinders, and lessen NOx emissoins. What do you think?

8

if you try to restrict (plug) the exhaust it will still fail.

change your cat and you’ll be good.

i remember when i replaced the cat on my vr6 swap and it still had high NO emissions. the tech said it was because they threw the car on the tester without much of a warm up. the cat works best when it is hot like after a hard drive

9

Yep, that’s what I think I gonna do…