Hey guys,
Sorry for the length....
A bit of a background: So I just bought a '90 1G DSM and I'm having some trouble passing smog here in CA. The previous owner said he never got it to pass and thus I got it for a steal because he didn't want to deal with it anymore. Anyway, the thing was having some major idle surge and fuel cut problems when I got it which I easily solved by replacing the BISS screw (it was totally missing, duh!) and reclamping the tubing going to the intercooler (it had had slid off and I'm sure air was escaping). So I figured with those huge air leaks fixed and the fact that the idle was now within the legal limit, I'd probably pass smog.
Of course I was wrong, but I did better then he had. I passed at 2500 rpms where he had faild, but didn't make it at idle (HCO 162, limit 120).
The guy had told me things that the shop he went to suggested could be wrong and one was that the cat could be on backwards. When I had originally heard this I seriously doubted it because the car has a custom downpipe, hi-flow cat, custom exhaust and muffler. No one installing all that could be that stupid to put the cat in backwards....
Given there are a lot of hacked up things on this car I decided to go under there and check to see if the cat was even real as it could have been gutted. It looked fine inside, very clean. I then noticed the CATCO lettering on the bottom and an arrow around it that pointed towards the front of the car, in the OPPOSITE direction of the airflow. WTF!
Now, if I were designing a product like this I'd point the arrow in the direction of the airflow so I'm about 99.99% sure that this @#$%@#!! thing is in backwards, but maybe for some silly reason this arrow means: "point towards the front of the car". Normally I wouldn't even consider this but after witnessing what might be a cat welded backwards into the exhaust, I'll believe anything.
So if any on has installed one of these CATCO cats before, let me know which way it goes in. I'm going to have to take it to a muffler shop and have them cut it out and weld it back into place and that will cost $$ so I want to make sure it's right.
Also, could having it in backwards damage it? I hate to go through the trouble of correcting it to get no additional benefit.
Also, Also, how much better might it work once it's in correctly or are my problems more fundemental (poorly tunned engine)? I know that the cat works in stages and that previous stages aid in the reaction of the next stage but I'd have to think that having it in backwards will still do _some_ good in reducing emissions. I guess another smog check will tell, but I wanted to get some thoughts.
Thanks all!
Sorry for the length....
A bit of a background: So I just bought a '90 1G DSM and I'm having some trouble passing smog here in CA. The previous owner said he never got it to pass and thus I got it for a steal because he didn't want to deal with it anymore. Anyway, the thing was having some major idle surge and fuel cut problems when I got it which I easily solved by replacing the BISS screw (it was totally missing, duh!) and reclamping the tubing going to the intercooler (it had had slid off and I'm sure air was escaping). So I figured with those huge air leaks fixed and the fact that the idle was now within the legal limit, I'd probably pass smog.
Of course I was wrong, but I did better then he had. I passed at 2500 rpms where he had faild, but didn't make it at idle (HCO 162, limit 120).
The guy had told me things that the shop he went to suggested could be wrong and one was that the cat could be on backwards. When I had originally heard this I seriously doubted it because the car has a custom downpipe, hi-flow cat, custom exhaust and muffler. No one installing all that could be that stupid to put the cat in backwards....
Given there are a lot of hacked up things on this car I decided to go under there and check to see if the cat was even real as it could have been gutted. It looked fine inside, very clean. I then noticed the CATCO lettering on the bottom and an arrow around it that pointed towards the front of the car, in the OPPOSITE direction of the airflow. WTF!
Now, if I were designing a product like this I'd point the arrow in the direction of the airflow so I'm about 99.99% sure that this @#$%@#!! thing is in backwards, but maybe for some silly reason this arrow means: "point towards the front of the car". Normally I wouldn't even consider this but after witnessing what might be a cat welded backwards into the exhaust, I'll believe anything.
So if any on has installed one of these CATCO cats before, let me know which way it goes in. I'm going to have to take it to a muffler shop and have them cut it out and weld it back into place and that will cost $$ so I want to make sure it's right.
Also, could having it in backwards damage it? I hate to go through the trouble of correcting it to get no additional benefit.
Also, Also, how much better might it work once it's in correctly or are my problems more fundemental (poorly tunned engine)? I know that the cat works in stages and that previous stages aid in the reaction of the next stage but I'd have to think that having it in backwards will still do _some_ good in reducing emissions. I guess another smog check will tell, but I wanted to get some thoughts.
Thanks all!
