I've been going through this since November and I'm running out of ideas. Recently I have done the following things to try to get my car to pass emissions:

1. Cleaned air filters
2. Changed spark plugs
3. Replaced smog pump
4. Replaced catalytic convertor
5. Installed new magnacore 10mm plug wires
6. Replaced vacuum lines w/ new silicon lines
7. Verified that ignition coils are within the specs stated in the FSM
8. Ran the "Guaranteed to pass emissions" formula through tank (obviously didnt work)

I do know that I have a missfire around 1100 rpm to 2500 rpm when there is no load on the motor. I'm pretty sure that the problem isn't due to the electrical system unless it is due to the crank angle sensor. I plan to check it tonight.
I can't really tell if the misfire continues beyond 2500 rpm due to the speed at which it occurs or does not occur. However the car still runs strong during mild to hard acceleration.
If it is not the crank angle sensor, then the only other option I can come up with is a faulty injector. Does this sound right to you guys?
One thing I have noticed is that this problem gets a little worse as the car continues to get warmer and warmer. After I have been driving for about an hour or so I will get an occasional backfire while decelerating or when shifting during hard acceleration.

Here are the results of my last three emissions tests and a graph from the most recent.
--------- HC---CO---Nox
LIMITS 1.00 12.00 2.50
--------------------------------------
TEST 1 1.30 23.03 2.23
TEST 2 1.08 24.93 1.62
TEST 3 2.11 20.62 0.57

The state of Arizona classifies the Rx7 as a 2 cylinder motor which I thought would make it more difficult to pass since it is in essence the equivelant of a 6 cylinder firing 6 times for every 1 revolution. But the manager at the emissions facility said that this makes no difference at all.

If anyone has any FACTUAL input it would be greatly appreciated.
If any of you gurus live in the Phoenix area please P.M. me if you are willing to help.

Thank you.

 

Is the PFC tuned?

 

Yes, It was tuned before I got the car. (supposedly)

 

Fresh oil and blowing out the little chamber under the elbow at the throttle body is said to help with emissions as well. And making sure the car (really the cat) is good and hot should also help. Drive it like hell for a while before the test and then let it idle in the parking lot while you wait.

Re-tuning the PowerFC could also make a big difference.

And if you really get stuck, you can run denatured alcohol in the gas tank to pass.

This doesn't help with the emissions troubles, but the rotary fires as often as a 4-cylinder (2 times per rotation of the main shaft), but the power strokes are 50% longer, which makes it 6-cylinder-esque in the smoothness department. A 6 cylinder only fires 3 times per rotation of it's main shaft.

-Max

 

Thanks, I forgot to put on the list that I changed the oil last night, and before the prior test, I went to blow out the little chamber before driving to the emissions place and it was completely dry so I didn't even bother this time. I've never found any fuel in there.

 

^

 

"Yes, It was tuned before I got the car. (supposedly)"

There is your problem, YOU need to learn how to tune with the PFC and lean out the fuel for the areas being tested, and it will pass.

 

I know how to lean out the maps before I have it tested, but I wasn't sure that it was my problem. I can't remember which was caused by what, but I think the Carbon Monoxide is caused by unburnt fuel, and the Hydrocarbons are from running lean. Both of which I have problems with and at the same points in the test. If you look at the chart they coincide with each other during hard acceleration which makes me wonder, am I running rich, or am I running lean.

I figured I would start with the known problems first. IE: misfire

I'm the first to admit that I don't know everything about the PFC and the rotary in particular. However I also know that I'm not a complete idiot. Which is why I haven't just started pushing buttons to try and solve the problem. I know my limits and adjusting my fuel maps w/out the proper diagnostic equipment is definately a bad idea in my opinion. As well as most peoples I would think.

Two years ago I passed with flying colors with the same maps so I wouldn't think they would be the culprit.

Please don't take me the wrong way. I appreciate your input, and your advice may be an answer to my problem. I'm just not sure how much leeway I have in adjusting the maps before I could possibly do damage and have to rebuild. We have the dyno test here in Arizona and the teenagers working at emissions like to get on it pretty hard when they have the opportunity.

 

Are they testing all the way up to 60 MPH? You could also ask the tech not to stomp the gas so much, rather get the car up to speed with less "foot". The key is to keep the car at or below 0 for boost. I know they have a time limit on how fast to get up to speed, but I'm sure they could help out a bit. As for the misfire, if slight, might be because you are running really rich. Look at your CO levels.

If you are really worried either get a WB02 setup, or just lean out the cells like Chuck said in the low RPM ranges where they test. Drive the car carefully, long enough to thoroughly warm up the main cat and get it tested. Then change the settings back. (write the numbers down first )

 

I have attached a copy of my fuel map. Does anyone have any recommendations as to what would be considered as safe changes?

 

Here is the trick to pass emissions (guaranteed).
Run a rubber hose from the air pump directly to the stock main cat (if it's not there, put it back on) drive to the test station and it's done. Remove the rubber hose and put everything back to the way it was. DO NOT drive around with the air pump directly connected to the stock cat, this is for the test only. If you leave it that way the cat will burn up.

 

That sounds like it is worth a try. I actually have two cats now, a brand new one for emissions and an old one for daily driving. I had flanges welded on both of them so I can swap them out after I pass emissions and just run the old one for daily driving until it is time to test again.