D7PNY

Got car back from MOT yesterday. Had to get CAT popped on for it to pass and the garage left it on so first time I've driven the car with cat in place.

Might just be 'placebo' but definitely feels a little strangled.

Car has massive K+N Filter, megan manifold and Invidia N1 exhaust (with bungs in day to day!)

Was just going to pop the decat on when I get a chance but I've searched and noticed a few threads with differing opinions about cars running lean with breathing mods.

With standard management am I in ropey territory if I put the decat back on with my other mods? and will there actually be any difference in performance or is it just placebo now that its less raspy?

Cheers,

Dave

U9aXy6Dn

I noticed a crisper, cleaner sound with a decat pipe on, however, the prospect of being pulled over by VOSA and given a fine has kept my decat in the garage.

Le8

Your set up is pretty loud. If you don't fancy changing the CAT every year I'll leave it off.

You don't get much extra BHP with Decat anyway. 3-5 bhp at most.

D7PNY

I run with the bungs in the exhaust day to day because without them it is a little asbo to be honest.

Going to whip out the bungs and see what it sounds/feels like with the cat fitted but without the bungs.

Changing the CAT doesn't bother me much to be honest and the decat would be back on already if I hadn't read stories of cars running lean with similar setups to mine.

Not looking to spend a heap on management etc (this is a 'cheap' track car for me so all about smiles for my ££'s).

If the consensus is that with my setup the decat is a no no without changing the management then the cat will stay on.

Cheers,

Dave

Andybill

have you thought about a fuel computer such as an apexi neo/vafc ? would bring all your breathing mods into line and ensure you that it isn't going to run rich/lean !

D7PNY

Never heard of them to be honest...I'm guessing you fit them and have the car set up on the rolling road to suit?

Ie. a remap of sorts without the cost of the programmable ecu? (Off to do a search on them)

Cheers,

Dave

Andybill

yeh its a cheaper/cruder version of a programmable ECU without the cost! s2konroids on here set mine up and was a significant gain from the standard ecu map.

The only problem is as far as im aware you only map for WOT (wide open throttle) but I guess that's where most people worry about running too lean/rich with breathing mods !

Mike's

I have been looking into the Apexi safc to be on the safe side as ive fitted a decat and induction.

I was also looking at getting an AEM / Inovite wideband o2 sensor and guage just to see what the AFR is doing (i already have a second welded in bung on my decat to fit a secondary o2 sensor)

Would this be a wise choice ?