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It was that time again and I had to get the seven to pass emissions in AZ. So just for fun, I took it in it’s current 311whp configuration, followed by a much more boring configuration.
Config 1:
Air pump in stock config
Rewired Supra pump
Greddy V mount
Bonez Downpipe and High Flow Cat
TGS exhaust
All 9’s for plugs
PFC tuned for 1 Bar @ 311whp
Config 2:
Air pump in stock config
Stock wired Supra pump
Greddy V mount
Bonez downpipe and High flow cat
TGS exhaust
Stock plugs (7’s in leading and 9’s in trailing)
Stock ECU
That stock ECU I think is the big ticket item here. Hope this helps the next person in getting their seven to pass.
Matt
PS
This was on 91 Octane and 1/2 oz/gal Idemitsu premix as well
AZ uses a shorter version ("IM147") of the transient dyno testing ("IM240" that some areas (such as parts of California) use. The IM240 test is like this:
For the IM147 they took the longer test and cut the first part of it off so that less time is spent waiting in line for testing, and cars are still warmed up when they do test. So it's easier to pass. They also use a bunch of updated math to predict whether it's going to pass while it's being driven, so that your Prius will pass after like 30 seconds and they can keep the lines moving. Each one of these zones is used as part of the math to figure out if your car is a "fast pass" clean Prius that can end the test quickly or if you've got, well, an Rx-7.
Because OP's HC and CO emissions were high, it is likely the result of the tune being too rich. The O2 feedback was probably turned off and the engine goes rich as soon as it goes into boost, as opposed to the stock ECU which is going to run the Air pump more and stay in closed loop more. The test results are also sensitive to driving style. If the driver uses more throttle the care will make more boost and run richer, which is especially bad for CO emission.
These tests are a lot harder to pass than tailpipe tests where they just run at idle or at a steady mph. So even if you have a cat you can still fail. Even if you had a good condition stock cat you could still fail due to the tune.
Matt, what’s with emissions? Thought you were in the Classic Car program? Amazed your numbers were THAT good with the stock ECU. Make sure to buy two year tags.
Liberal states like california have a visual inspection as well as an emissions test. Any tampering with emissions equipment without Air Resource Board is an automatic fail.
Its a pretty interesting test to watch. I was used to like an idle, 15mph, and 25mph test. They basically drive your car like it’s on the road and it sniffs the exhaust. It mimics like getting on the highway as they get all the way into 5th gear. You’re 100% correct that my tunes map is very rich and that O2 feedback is turned off.
@RCCAZ_1
I highly considered joining the ranks of the classic car clubs :P but classic car insurance was too expensive for me. It was about 2 hours of work to get it back to this condition so that’s not too much work. If I was ported, didn’t even own a cat, and basically knew I had no chance of passing, I would definitely get on that train for no emissions. You bet your pants I got 2 year tags 😁
@fuhnortoner
Yea CA is definitely harder to pass a visual. AZ tech guys just asked me, “where’s your charcoal canister?” I told them it was under the car by the gas tank and then they marked it uninspectable on the computer. They didn’t care at all that I had a full 3” exhaust, high flow cat, and a Greddy V mount. :P In California, I remember them checking the numbers on a cat to make sure that it was for that engine when I went to a BAR inspection for a swap. They’re very particular.
Matt, I JUST had mine tested a couple months back and I want to say my numbers were very similar with a stock ECU. I've considered just going with classic car insurance too, but there are a lot of variables involved where I decided not to at this point. I'm hoping to get a PFC in the next year and a tune, so good information to know.
