I just wanted to pass on my experience in getting my 7MGTE to pass emissions testing this year. Maybe it will answer some questions that have not been asked or expand on some that were.
It's a 91 with a new engine build. Mods as follows:
- Full rebuild (machine work, balance, JE Pistions, MHG, ARP, etc)
- AFPR
- 3" Exhaust (57 trim CT26 ---> Zoowen Re-circulated DDP ---> Carsound Hi-Flow CAT ---> Vibrant Performance Ultra-quiet Resonator ---> Borla 3" IN - 2 x 2.5" in OUT)
- All emissions equipment installed except pre-cat.
- IC hard pipes
- Blitz BOV (Re-circulated)
Just as my build was being completed, I was already due for my Smog Check. The last 2 times I have been directed to a Test-only station. This year I was not (I barely passed the last 2 times).
Still within the engine break-in period, I decided to get a pre-test done ($40), just in case I failed horribly, it would not be transmitted to the DMV.
I took the advice of several posts on this forum regarding warming up the CAT before the test.
See the image below for details of the Smog Check Vehicle Inspection Reports:
VIR A - My first pre-test run. Obviously failed.
VIR B - My second pre-test run. Better, but still failed. The smog tech warmed the car up a little more on the dyno before making another attempt.
At this point the tech recommended a new CAT.
VIR C - My first run with the new CAT. PASS!
VIR D - I dug this up from archives and added it just for the sake of comparison. I cannot find the initial change of ownership smog check data.
Observations:
- I always knew before I started on my build that I would tackle any possible emissions issues head-on. I intended on passing CA emissions and was going to give it a reasonable effort before ever considering the alternatives (methanol or similar and $$$pecial smog checks).
- The tech was not at all concerned with the possible non-CARB certified items in my engine bay. He bought in some of the other shop techs to visually enjoy Driftmotion's great work.
- I was very surprised that my brand new hi-flow cat did not help me pass emissions, but then again there were some comments made on some old forum posts that may have indicated the possibility of this scenario.
- Since I did not have the time, I let the tech find a replacement CAT. I understand it would have cost more to do it this way, but I could not take any more time away from work to screw with my car at the moment. The tech did not know the brand of the replacement 3" Main CAT or whether it was a hi-flow type. I took a look at it and I could not identify any markings, but this CAT was about 30% longer then the OEM Main CAT and 40% longer then the Carsound Hi-flow I already had installed.
- The drive home revealed some other things:
- The exhaust resonance I felt inside the car between 2000-2300 RPMs was subjectively cut down by 20-30%. It was definitely noticeable.
- There was no noticeable difference in performance response, but I am still breaking in the engine, so this might be a non-factor.
- As already previously stated in these forums. You can pass CA Emissions or similar with just the Main CAT. The question to ask is "Can you accomplish it with any brand CAT?" I got mine off ebay for about $90. But I had a nagging thought after the purchase regarding whether this was a smart choice. I wanted the Random Technologies CAT, but decided to be spend less instead.
I hope this information is useful to someone who is worried about passing emissions testing. I know I was.
It's a 91 with a new engine build. Mods as follows:
- Full rebuild (machine work, balance, JE Pistions, MHG, ARP, etc)
- AFPR
- 3" Exhaust (57 trim CT26 ---> Zoowen Re-circulated DDP ---> Carsound Hi-Flow CAT ---> Vibrant Performance Ultra-quiet Resonator ---> Borla 3" IN - 2 x 2.5" in OUT)
- All emissions equipment installed except pre-cat.
- IC hard pipes
- Blitz BOV (Re-circulated)
Just as my build was being completed, I was already due for my Smog Check. The last 2 times I have been directed to a Test-only station. This year I was not (I barely passed the last 2 times).
Still within the engine break-in period, I decided to get a pre-test done ($40), just in case I failed horribly, it would not be transmitted to the DMV.
I took the advice of several posts on this forum regarding warming up the CAT before the test.
See the image below for details of the Smog Check Vehicle Inspection Reports:
VIR A - My first pre-test run. Obviously failed.
VIR B - My second pre-test run. Better, but still failed. The smog tech warmed the car up a little more on the dyno before making another attempt.
At this point the tech recommended a new CAT.
VIR C - My first run with the new CAT. PASS!
VIR D - I dug this up from archives and added it just for the sake of comparison. I cannot find the initial change of ownership smog check data.
Observations:
- I always knew before I started on my build that I would tackle any possible emissions issues head-on. I intended on passing CA emissions and was going to give it a reasonable effort before ever considering the alternatives (methanol or similar and $$$pecial smog checks).
- The tech was not at all concerned with the possible non-CARB certified items in my engine bay. He bought in some of the other shop techs to visually enjoy Driftmotion's great work.
- I was very surprised that my brand new hi-flow cat did not help me pass emissions, but then again there were some comments made on some old forum posts that may have indicated the possibility of this scenario.
- Since I did not have the time, I let the tech find a replacement CAT. I understand it would have cost more to do it this way, but I could not take any more time away from work to screw with my car at the moment. The tech did not know the brand of the replacement 3" Main CAT or whether it was a hi-flow type. I took a look at it and I could not identify any markings, but this CAT was about 30% longer then the OEM Main CAT and 40% longer then the Carsound Hi-flow I already had installed.
- The drive home revealed some other things:
- The exhaust resonance I felt inside the car between 2000-2300 RPMs was subjectively cut down by 20-30%. It was definitely noticeable.
- There was no noticeable difference in performance response, but I am still breaking in the engine, so this might be a non-factor.
- As already previously stated in these forums. You can pass CA Emissions or similar with just the Main CAT. The question to ask is "Can you accomplish it with any brand CAT?" I got mine off ebay for about $90. But I had a nagging thought after the purchase regarding whether this was a smart choice. I wanted the Random Technologies CAT, but decided to be spend less instead.
I hope this information is useful to someone who is worried about passing emissions testing. I know I was.