Brand new first time rotary owner, 2006 Shinka w/ 78k miles on car. As the title above says, I have noticed an intermittent stumble/hesitation and experienced an occasional misfire when under load at higher RPMs. The car also occasionally surges with much higher power at about 6k rpms, which indicates it could be a bad SSV solenoid. This doesn't happen all the time and it seems to happen more from 1st to 2nd or 2nd to third. I have searched and it looks like there are many threads detailing this, which basically include replacing everything...lol...so that is what I am slowing doing I guess to nail down the problem.

So far, I have replaced the following related to this issue:
OEM Cat to BHR Midpipe
1st gen BHR Coils to newest BHR Coils
New Plugs and MSD wires, matched trailing and leading
Cleaned MAF (will clean again)
Cleaned ESS
Seafoamed car 1x
Seafoam in gas tank
Cleaned lots of electrical components
New Odyssey Group 35 Battery (oversized)

Up next is running injector cleaner (chevron likely) and a compression test. Compression should be good even though the motor is high mileage - no hot start issues, fires right up (I did upgrade the starter). I will also try re-torquing my spark plugs with a torque wrench this time after the compression test!

I know that I may be experiencing fuel pump related issues so I am looking into whether it's worth modifying the S2 fuel pump assembly or just getting a new S1.

Lastly, I know I need to start checking my codes - no codes when I bought it but I have the O2 sensor code since I removed the CAT. Definitely has misfire as the CEL blinked and I felt it.

So - I'm guessing I should purchase MazdaEdit and pick up a Tactrix 2.0 soon. Any other recommendations? Are the knockoff Tactrix 2.0 good? I'm not trying to cheap out but the more I save the more that goes into the car for fun stuff!

 

How are you checking codes?
The blinking CEL is not from the decat, that's a misfire. P0420 from decat is a solid CEL
There should be a misfire related code.

 

Yes, I need to get a code reader, was thinking of the Tactrix 2 w/ mazdaedit to clear codes and view? I have a solid CEL from the cat delete - this came on the moment I swapped.

The blinking CEL happened before I swapped, and has only happened once since. Still trying to track down everything that could be related as I was really hoping it was just the CAT or plugs.

 

Might need to just reset the ESPS. With the car in the run position (Not started), Depress the brake pedal quickly about 20 times. You should see the oil pressure gauge go to mid then reset. That can sometimes clear misfires.

 

Thanks, should have mentioned - definitely did that multiple times! I've had the battery disconnected almost every night since I've owned it, lol. It's been a recent obsession keeping me awake til midnight every night, either up on jackstands or pulling the intake box every other day!

 

Disconnecting the battery won't reset the ESPS. Its only possible through the brake pedal stomp. The car keeps the data even if the battery is out of the car.

 

I should have clarified - I understand this, each time I disconnect/reconnect the battery, I go through the same procedure. Wheel left/right, ignition off, ignition on and brake stomp til the oil pressure gauge goes up. I've done it 4-5x now so I'm an expert. My wife thinks I'm nuts.

 

Ok so you were resetting it. The misfire could be an ignition system issue but it seems like you got new ignition components. You've removed the cat so that won't be the cause. Only thing left is a fueling problem or low compression really.

 

Also what's the original cat look like?
If it's the OEM with intact strata you should be good.
If it's broken up or looks like a replacement you could have broken pieces blocking the catback exhaust.

 

Good point. Funny story, same issue with mine. Was pulling peices of my cat out from the back of the LIM. No idea how they got all the way up there but they did.

 

Hah didn't think to check this but I will. I have a brand new Racing Beat catback sitting in a box at home so all the more reason to throw that on soon. Been spending a LOT of money on parts good thing its a labor of love!