Fuel Mixture With Aftermarket Parts

[Herblenny]

I have had problems with my 8 not running well for a while now. Mazda ran a diag a couple of times, and it always looked like the problem was with my fuel mixture. The car wants to run too rich. I installed the RP Supercat on my 8 back in September and didn't start having any issues untill about 2 months ago.

I pulled the supercat off and reinstalled the OEM cat a few of weeks ago, and cleared both the NVRAM and the KAM. (I only did this because Mazda kept blaming the aftermarket part) But as I expected, the problems didn't go away. Even after driving around 300 miles (mostly interstate) on the car after the reinstall. So I let Mazda have the car for a couple of weeks while I was out of town. I got the car back this morning, and it does seem to be running better. But no more so than it does every time I reset the NVRAM, which is always short lived. Mazda is saying that because the PCM learns progressively, it needed longer to work through the bad information the supercat had been sending it.

So here is where I'm looking for some input from the forum....
1) Does it sound like Mazda has a legitimate argument considering the car ran fine for 4 months with the supercat installed?
2) Has anyone else had a similar issue with the RP Supercat, or any aftermarket converter, after installing it on their 8?

I'm driving to Oneonta for a funeral this afternoon, which is little over an hour in both directions. So I'll update my post after the trip to see if the car is still running better, or if it looks like Mazda just reset the memory.

Update: It looks like I was right. Mazda doesn't seem to have done much more than reset the ECU. It was as bad yesterday as ever. It even reminded me of a couple of symptoms that had slipped my mind:

Very sluggish throttle response

Have had to drop down to 3rd to accelerate uphill - when driving around 50mph+

almost stalls at red lights - and has stalled a couple of times

Coverter gets pretty hot

Car backfires - particularly when I shift

When the A/C compressor turns on the RPMs drop, sometimes as much as 500 (tested this at low RPM though - specifically with car in neutral, dropped from 2.5k to 2k
-addition to that- when idling with the A/C on, the RPMs want to hover just above 500 and if I'm not mistaken it should move from 800 to 1k to compensate for the added drag

Car feels like it has what I can only think to describe as a "miss". It feels a little like someone touching the brake for a split second as I'm driving, The timing of it is completely erradic, and it's most noticable when I'm maintaining a constant speed. Generally with the RPMs holding very steady (between 4.5-5k)

Symptoms are always the worst in the afternoon when it's warmer. The car still hasn't thrown a CEL though.

[eppo37]

I have had problems with my 8 not running well for a while now. Mazda ran a diag a couple of times, and it always looked like the problem was with my fuel mixture. The car wants to run too rich. I installed the RP Supercat on my 8 back in September and didn't start having any issues untill about 2 months ago.

I pulled the supercat off and reinstalled the OEM cat a few of weeks ago, and cleared both the NVRAM and the KAM. (I only did this because Mazda kept blaming the aftermarket part) But as I expected, the problems didn't go away. Even after driving around 300 miles (mostly interstate) on the car after the reinstall. So I let Mazda have the car for a couple of weeks while I was out of town. I got the car back this morning, and it does seem to be running better. But no more so than it does every time I reset the NVRAM, which is always short lived. Mazda is saying that because the PCM learns progressively, it needed longer to work through the bad information the supercat had been sending it.

So here is where I'm looking for some input from the forum....
1) Does it sound like Mazda has a legitimate argument considering the car ran fine for 4 months with the supercat installed?
2) Has anyone else had a similar issue with the RP Supercat, or any aftermarket converter, after installing it on their 8?

I'm driving to Oneonta for a funeral this afternoon, which is little over an hour in both directions. So I'll update my post after the trip to see if the car is still running better, or if it looks like Mazda just reset the memory.

Update: It looks like I was right. Mazda doesn't seem to have done much more than reset the ECU. It was as bad yesterday as ever. It even reminded me of a couple of symptoms that had slipped my mind:

Very sluggish throttle response

Have had to drop down to 3rd to accelerate uphill - when driving around 50mph+

almost stalls at red lights - and has stalled a couple of times

Coverter gets pretty hot

Car backfires - particularly when I shift

When the A/C compressor turns on the RPMs drop, sometimes as much as 500 (tested this at low RPM though - specifically with car in neutral, dropped from 2.5k to 2k
-addition to that- when idling with the A/C on, the RPMs want to hover just above 500 and if I'm not mistaken it should move from 800 to 1k to compensate for the added drag

Car feels like it has what I can only think to describe as a "miss". It feels a little like someone touching the brake for a split second as I'm driving, The timing of it is completely erradic, and it's most noticable when I'm maintaining a constant speed. Generally with the RPMs holding very steady (between 4.5-5k)

Symptoms are always the worst in the afternoon when it's warmer. The car still hasn't thrown a CEL though.