PUR NRG

This thread is to post various CELs you may encounter after installing the interceptor, what they may mean and how you dealt with them.

PUR NRG

P0300 Random/multiple cylinder misfire detected

From Scott:
This code is a misfire detection. Although it could be detonation, this code is also common from the system running too rich. A misfire is occuring and the factory knock sensor hears the noise in the combustion chambers and is letting you know. Removing the factory N/A plugs and switching to the colder (harder to foul) surface gap style may resolve that. Of course, wideband tuning is still required to get the most from your setup. The spark plugs we prefer are the traditional plugs we have used for forced induction street cars for years. BTW, Mazda used this style of spark plug on the Turbo2 and FD Rx-7's for a reason, they used 7's for leading and 9's for trailing factory boost level cars. We prefer all 9's for added safety.

PUR NRG

P0410 Secondary air injection system malfunction

From Scott:
The air injection code is present because the factory E.C.U. thinks "it's really rich, somthing must be wrong with the air injection system". During the Intial testing this code was present but after tuning stopped reoccuring.

PUR NRG

P0172 System too rich (Bank 1)

From epitrochoid:
a shot in the dark, but can we use the greddy dongle on the PCM still to fool it?

From Scott:
Please DO NOT connect any emanage dongles to the Interceptor-X wiring. If you notice the codes that have been popping up are because the system is too rich. There is actually nothing "wrong" other than the factory ECU is seeing the "rich" values and determining that they are to "rich" for a stock non turbo car. The factory ECU is correct, the AFR's these guys are viewing are too rich for a non-turbo car. If you run a Turbo car at 13.0-1 AFR's hard (under boost) you will at some point have an engine failure. As I stated before, the CEL will perform as Mazda intended. If we fool the factory O2 sensor then using it to monitor AFR's will no longer be accurate.

From PUR NRG:
I got this code every now and then with the eManage as well. I think it's unavoidable and something we'll have to live with.

adrian-1

I've ordered an O2 simulator that should work with the RX8. This should keep the "System too rich" CEL from appearing.

It should arrive by next week. It's from Caspers Electronics and model 104052. Info here.

epitrochoid

hmm...looks promising. hopefully it will work out for you (and everyone else with a midpipe!)

definately keep us posted.

rkostolni

That simulator is only for the rear O2's though. I believe the front O2 is what is used to determine A/F mixtures, the rear O2 just measures catalyst degradation. So I think an error code for the cat would need the rear O2 simulator, but since you get an error code for improper A/F, I think you need a front O2 simulator, or a wideband simulator.

adrian-1

I see your point. It's not really an issue with the midpipe (or hiflow cat). Others running the stock cat will still get the too rich code.

ScudRunner

I finally got my CANScan working, and here are the codes I found.

I also had the misfire, fuel volume regulator control circuit/open and system too rich codes (P0300, P0001 and P0172). I had P7200 and P4700 pending, but haven't looked them up yet to see what they are; the CANScan software didn't recognize them.

bedrock83

po300 is what igot when i switched my cat for my midpipe. It never goes away, it always comes on if my car were to hit 90+ quickly

MadDog

Not so fast...
misfire does not equal detonation. If you read the technical stuff on how this code is generated, its looking for a lack of e-shaft movement during the time when the combustion process should be taking place. If the e-shaft hasn't moved far enough, then you didn't light-off the mixture. This code is NOT a detonation code. As far as I've been able to tell, there is no code when the knock sensor "hears" detonation. (BTW: the knock sensor does not hear misfire, there is nothing to hear...) The ECU simply retards timing. No CEL is thrown.

Also, colder plugs are easier to foul. If you aren't running boost enough, the colder plug tips don't get hot enough to clean themselves. This leads to fouling, which can cause misfire when the plug doesn't light the mixture. The whole reason to run colder plugs is to reduce the chances of detonation. A hot plug tip could light the mixture too soon. Running colder plugs is at the added risk of fouled plugs

PUR NRG

Agreed. However one of the possible causes of misfire is detonation. (I do not know if the misfire code can also be triggered because it rotated mroe than expected, or if that might happen due to boost. But that's another story.) So let's break down the sequence:

• Misfire means the shaft did not rotate as much as expected.
• The shaft did not rotate enough due to lack of power.
• Lack of power can be caused by three things:
  • The fuel/air mix did not ignite
  • The fuel/air mix did not completely ignite
  • The fuel/air mix ignited too soon (detonation), which also results in loss of power

I think that's why Scott recommends the RX-7 plugs. They have a larger gap (which isn't as good for boosted cars) but more than make up for that by having four potential locations for the spark to cross the gap rather than a conventional electrode's one.

rkostolni

Hey Adrian, did you ever get that O2 simulator. I'm curious how it worked out. I was also thinking about just trying to move the O2 sensor in and out a little to try to manually get the right readings. I don't know how effective it would be, but this thread seemed to have some success.

https://www.rx8club.com/showthread.p...2&page=2&pp=15

adrian-1

The O2 simulator did come in but I haven't put it in. It won't clear the "system too rich" code. It's meant to clear the CEL for using a testpipe.

rkostolni

If the simulator doesn't work out, then I think what I'm going to try to do when emissions time comes around is send the factory computer a temp signal from Greddy's cold temp dongle under boost and send the Interceptor the true water temp signal. I'll have to take the cold loop dongle apart to see exactly how it works, and determine if it needs to be diode isolated or not to make sure it doesn't affect the Interceptors true temp signal, but should be easy enough to integrate. Although, if someone who still has the Emanage hooked up could take a couple voltage measurements that could save me from having to reverse engineer it. Now accepting volunteers.

To trigger it I saw the Interceptor has an unused ECU option for a boost dependent output in one of the setup screens, so I'm thinking if I set that to 0"HG and get info on which wire that is from Scott, that should be able to trigger the cold temp dongle much like the emanage did. It might need some voltage conversions, but no big deal. I'm pretty confident this should work to eliminate any CEL related to the system being too rich.

PUR NRG

Stupid question: if necessary for emissions testing, why can't you disconnect the battery to reset LTFT and remove the interceptor? The stock ECU should be fine for engine management as long as there isn't any boost. My understanding is the greddy turbo doesn't boost unless you go above 3000 rpm, which doesn't happen during an emissions test. Therefore the setup I described should work, right?

rkostolni

The computer keeps track of when it was reset last and will show a code that notifies the OBD reader if the computer has not seen sufficient drive cycles to accurately determine if the car and emissions equipment is working properly. Now by "drive cycles" I don't know exactly what the computer looks for. I know it looks for number of times the car has been started, but I don't know if it looks to see if the car has been operated under open-loop mode, or something similar.

Also, I wouldn't feel comfortable handing my keys to the emissions person with the car running only on the stock computer, I know there's no reason they should be on the gas enough to get into boost, but if they did, the motor would be done.

PUR NRG

I'm pretty sure "drive cycle" is each time the car has been driven. However are you sure about that code? I can imagine a situation where a car fails emissions, gets it repaired and immediately gets smogged again. If the code existed how could that scenario happen?

slavearm

You guys really need to introduce yourselves into the darker side of emissions testing and be willing to pull out a couple of Franklins. Make life a lot easier on yourselves.

MadDog

Amen bro.

PUR NRG

Not if you don't know who to give them to. Some people are kinda scrupulous that way and might think you're pulling a sting on them.

slavearm

Not everyone will do it, but most everyone in the business knows someone who will.

And of course, anyone who has been tuning RX-* for awhile HAS to know someone.

PUR NRG

I'm quoting myself, but I ran this theory by Scott and he thinks it might have some merit. He's going to mull it over more and think about it.

Here's my (wild ***) theory:
1. E-shaft rotation is determined by amount of fuel, air and ignition timing. More power means it rotates faster, less power means it rotates slower.
2. Misfire is triggered if the e-shaft rotates more or less than expected by the ECU.
3. Under boost, the ECU thinks there is less fuel and air in the combustion chamber. The ECU also thinks the ignition timing is happening sooner than it actually is with the Interceptor.
4. The ECU thinks the e-shaft will take X milliseconds to reach a certian position but that expectation is thrown off by what the Interceptor actually does. As a result the ECU throws a misfire code.

It's a nice theory but doesn't explain why all turbo cars are getting this misfire code.

rkostolni

Adrian, did you try the O2 simulator?

adrian-1

No, the simulator won't do anything for the too rich code.