Just speculating, but it is possible the Softronic is more forgiving on the MAF readings and possible you would be getting a CEL if running stock. You may want to revert to stock ECU for a while and verify everything is working properly before applying the Softronic flash. My .02.

 

I noticed a very slight hesitation off idle at light throttle after the cat/muffler install. Haven't reset the ECU yet. Runs strong @ WOT.

Unfortunately my butt dyno isn't calibrated all that well so I can't really feel a 20hp difference.

 

I had A.W.E HJS 200 cell CC's on my '06 C2S....No codes, no issues, Sweeter exhaust note to be sure, I loved the WOT music of that!!!!!

 

No issues with my AWE/HJC 200 cel Cats and softronic upgrade

 

Personally I would not do 200 cell cats with out doing a good ECU re-tune. Remember everything has to work togther as a system. You change 1 or a few things and you have to change something else...this goes with engine mods or suspension mods.

 

+1 on that. It looks like its a must

 

Other than being pretty loud on my 997 C2S Cab, I loved the AWE Cats - they worked exactly as advertised from the moment I installed them.

My guess is MAF cleaning will help you out. Have you considered spark plugs? Did this behavior occur prior to installing the cats?

Cheers,
Gundo

 

Nope, car was very consistent on stock exhaust, but, again, all that time outside temperatures were in 70s.

It is a second day after second ECU reset - car still goes as a rocket. It is either outside temperature or something just settled down somewhere. I ordered online those secure T20 bits, so, will wait a bit. They will arrive some time next week. But I feel reluctant now to mess with MAF if car runs OK.
Plus I will need to find some time to install IPD plenum and hopefully find even more time to visit dyno, well...

All that stuff starts quite negatively reflect on my work, I got to say. This Porsche mod extravaganza transforms into some sort of a full time job.

 

I got set of secure bits today, unplugged battery, extracted MAF, soaked it in this spray multiple times, sprayed it entirely inside and out, dried it up and got it screwed back. Well, after it dried up in 20 minutes or so I took it for a drive - I got to say, notice on the box saying 'you`l gain 5-10hp' is pretty accurate.

Car goes definitely a bit smoother now at high revs, pulls more equally, so, I guess it is probably really worth doing this spray thing every 10K miles or so.
Now last thing left to do is to put new spark plugs in. Then it will all become very boring as I ran out of anything left to do with it at all other than just driving it around.

 

The gain you feel is probably more from the ECU reset more than anything. You didn't install a Plenum by chance at the same time . Just kidding, glad it's all running better for you now.

 

Nah, I did reset poor thing 3 times during last 6 days alone, I now know how it runs with my eyes closed.

Plenum was done Saturday, and I ran it yesterday and today morning, after reset. What I had was pretty specific - some sort of subtle pull force irregularities or fluctuations at full throttle, like timing was jumping back and forth. It seems to be gone now, at least after 7 miles loop on local roads. Long drive on highway will show it better tomorrow. Anyway, I will not rest this case until I change everything I can reach, spark plugs are the last part of this stupid puzzle.

Car runs terrific now, way better than stock. May be it has no sense to change plugs, but it is so cheap - why not to do it anyway, car has 44K miles now, so, it`s time anyway.

 

Good to know. Really glad you got it all running nicely. I know how frustrating that can be.

 

Really? I don't know.
It seems that my cats made a huge difference without any need to retune the ECU, although I did let it reset (battery was disconnected during install and overnight). I think the ECU can adapt pretty quickly to the new less restrictive cats, and that a reset is enough.

Can anyone (Mike at AWE, Sharkster, anyone?) chime in with their experience here?
CATTMAN