How to pass smog in an '84 or '85
11-08-11, 01:46 PM
#1
Full Member
Thread Starter
How to pass smog in an '84 or '85
Here's a tip that was passed onto me by someone I knew at a wrecking yard.
Say you're having trouble getting your '84 or '85 to pass smog?
Well, there is an easy way to deal with it.
1) As you know, there are three cats in a line out the exhaust. It seems that Cat#1 self destructs taking #2 with it. #3 is more robust but it will not pass smog if your cats are disintegrating.
2) The car absolutely has to be able to pass the physical inspection, missing air pump:FAIL. So ensure you either leave everything hooked up or at least keep your parts in a cozy part of the garage.
3) The timing has to be exact, they'll fail you for that and they will not adjust it for you.
4) So, you know you've got cat problems huh? Well, here's the trick.
a) Remove all three cats.
b) Take the first two (the closest to the engine) and hollow them out, most of the time, they've done that for you.
c) You need to get the big cat from the newest 2nd gen you can find.
d) Unfortunately, this cat will not bolt onto the exhaust pipe so you need to get a sawsall and elongate the mounting holes on the exhaust side. I can't remember if you have to do this on the inlet side.
e) Take the two hollowed pre-cats and mount them normally and then mount the big third cat, don't forget the line that opens the extra ports on your 6 port engine.
Now, a physical inspection will pass with no problem. When you go to get your car smogged, drive it for a while to ensure the third cat lights off, drive for at least 1/2 an hour. When they do the test, make sure they don't keep the cars waiting so the cat cools down.
Relish the fact that your gross polluter (at least in California) just passed smog. I've done this on 2- 1st gens and it works beautifully. The guys that told me about it said they'd never had a fail as long as the timing was on and all the pieces were there.
After it passes, put the timing back to where it performs best but without the destructive pinging.
Don't forget to gloat over the man
Say you're having trouble getting your '84 or '85 to pass smog?
Well, there is an easy way to deal with it.
1) As you know, there are three cats in a line out the exhaust. It seems that Cat#1 self destructs taking #2 with it. #3 is more robust but it will not pass smog if your cats are disintegrating.
2) The car absolutely has to be able to pass the physical inspection, missing air pump:FAIL. So ensure you either leave everything hooked up or at least keep your parts in a cozy part of the garage.
3) The timing has to be exact, they'll fail you for that and they will not adjust it for you.
4) So, you know you've got cat problems huh? Well, here's the trick.
a) Remove all three cats.
b) Take the first two (the closest to the engine) and hollow them out, most of the time, they've done that for you.
c) You need to get the big cat from the newest 2nd gen you can find.
d) Unfortunately, this cat will not bolt onto the exhaust pipe so you need to get a sawsall and elongate the mounting holes on the exhaust side. I can't remember if you have to do this on the inlet side.
e) Take the two hollowed pre-cats and mount them normally and then mount the big third cat, don't forget the line that opens the extra ports on your 6 port engine.
Now, a physical inspection will pass with no problem. When you go to get your car smogged, drive it for a while to ensure the third cat lights off, drive for at least 1/2 an hour. When they do the test, make sure they don't keep the cars waiting so the cat cools down.
Relish the fact that your gross polluter (at least in California) just passed smog. I've done this on 2- 1st gens and it works beautifully. The guys that told me about it said they'd never had a fail as long as the timing was on and all the pieces were there.
After it passes, put the timing back to where it performs best but without the destructive pinging.
Don't forget to gloat over the man
11-08-11, 04:39 PM
#2
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,829
Received 2,596 Likes
on
1,844 Posts
yep, if the air injection is working like it should then you should have no trouble passing smog....
i just smogged an FC, it did something like 22 HCs, 0.03co and 231nox. car has 200k on the engine, no precats and the main cat is in horrible shape!
actually the only thing that i've smogged that was cleaner than the Rx7's is the Rx8. the piston cars pass, but they are usually dirtier than the rotaries
i just smogged an FC, it did something like 22 HCs, 0.03co and 231nox. car has 200k on the engine, no precats and the main cat is in horrible shape!
actually the only thing that i've smogged that was cleaner than the Rx7's is the Rx8. the piston cars pass, but they are usually dirtier than the rotaries
Thread
Thread Starter
Forum
Replies
Last Post