asagi

Hi all

Just had my MY00 decatted (standard apart from that) and it sounds and goes great, however when driving home tonight I was'nt sure if the car has a slight low-mid range misfire on part throttle.

Because I'm getting alot more sound after the decat, not sure if I'm mistaking the off-beat rumble with a misfire. Car seems to go well so maybve I'm being paranoid.

Anyone had misfires after decating??

BAZ

R Johnson

hi my car has got the same problem,its a MY00 UK std apart from full decat,and its started misfiring between 2000 and 3000,its getting worse,any idears anyone ?

Tidgy

think im right with the bit i say but not 100%
decatting changes the back pressure so they advise resetting ecu, however if you've been running it for a while should have lernt anyway. but you may be getting backfires not misfires due to unburnt fuel not being picked up by cat, aka pops and bangs and maybe odd flame, my classic pops and bangs all over the place especially on downshift and if you hover slightly on throttle at 3k rpm

New_scooby_04

iTrader: (4)

You won't need to reset the ECU on an MY00 mate; they'll adapt quickly.

If the car's performance is ok, i.e. it does not feel like anything is up and you're just hearing popping, particularly on the over-run, this is -as Tidgy says- unburnt fuel igniting on the exhaust. The reason this is happening post decat, is that the ECU is responding to the better exhaust gas flow by adding more fuel.

A remap will sort it out and unleash the full benefits from the decat.

Ns04

Tidgy

cheers for the clarification, also helps get more poping and banging too lol

R Johnson

my problem dosnt include any pops or bangs,its just a total flat spot between 2000 - 3000 revs,but only on part throtle,floor the throttle and it pulls ok,the problem is intermitant and first started after i fitted the decat downpipe. I refitted the downpipe cat at the weekend but the problem remains,i am now thinking that it could be nothing to do with the decat downpipe. I am thinking possibly faulty MAF, any idears ?

Tidgy

problem is it could be any number or combination of things, best bet is don't thrash it incase it is maf or something serious, and get it up to a specialist ASAP.
where abouts in uk are you?

Jay m A

iTrader: (2)

There is an emissions feature on the MY00 ECU - if you hold part throttle for a few seconds then floor it the power is flat. The way to get around it (if holding part throttle) is to come off the throttle then floor it, rather than flooring it.

Perhaps this is the flat spot you are getting? There are quite a few posts on this, try the search.

R Johnson

thanks for those comments,i think i have now sorted it,i swaped the lambda sensor last night,also cleaned the coil HT terminals and its been fine today, just hope it stays fine!
just to clarify things,it was driving awfull between 2000-3000 as if either fuel or ignition was not present i e my description of "flat spot" probably an understatement !