Low performance during acceleration - SOLVED

[gsxr]

Usually, clogged cats won't affect idle noticeably. At least if they are not massively clogged, in which case power will be sub-300E.

With semi-clogged cats, the car can run & drive totally normal, but power will be reduced at higher RPM (say, 4000+). With this failure mode, you cannot tell there is a problem without a dyno / dragstrip / performance box to see that HP or acceleration, respectively, are sub-par.

 

[maw1124]

+1

I could only tell the difference when trying to pass at highway speeds. Of course, slapping it into 3rd solved that problem. Later I noticed the cats were rattling so it gave me an excuse to do what I wanted to anyway. I could tell the difference at high RPM afterward. But no running problem led me to that change. The car was new to me when it was "struggling" to pass -- I didn't know the difference before but could certainly tell the difference after.

maw

 

[nocfn]

I heard this somewhere: when in doubt, cut them out. I suspect that applies to 25 year old+ cats. Hell you would be the first non-methhead to grab a net $800 bucks for a used cat that wasn’t stolen.

 

[dionphaneuf]

Well, this tool is crap. The hose is about 6 feet long - easy enough to lengthen with a jumper hose and male to male fitting, but seriously, if you're going to include a hose just make it 8-10 feet so it can easily reach into the drivers lap. It was in the footwell here bc I couldn't find a more efficient route. When I went to remove the screw in fitting both o rings were cooked and the hose ripped off at the barb. This is a one time use tool.

In any case, the gauge dial is below - anything in the red is bad. Idle was fine, but during WOTs I was deep into the red indicating a restricted exhaust. New cats are in my future it appears. Whether or not this solves my other issues will be covered in another thread, but thought I'd show this tool in action here (along w a gratuitous tunnel pull ). Other times it got waaaay deeper in the red, just hard to film.

 

[maw1124]

But on the bright side... new cats... and better breathing... run that thing up the coast for a few hours and back with new cats and almost any trace of carbon will be burned off. Then find someone to do a BG decarbonation service. You'll have a new engine.

maw