De-cat remap Query

[Mr mav]

Just wondering if i decat my Z, will there be any issues, such as the engine management light poping up? or will the car require a map? the car is standard apart for a japspeed K1 exaust

 

thanks

[spursmaddave]

Yes it will most likely throw a fault unless you get spacers or have a remap and you would need a remap to get the best out of them anyway from what I have read on here HFCs or decats make the engine run lean but someone more knowledgable can confirm that

 

Must be mighty loud with a K1 and decats

[Mr mav]

cheers for the advice, may have to throw the bungs back in

[spursmaddave]

cheers for the advice, may have to throw the bungs back in

 

Pardon?

[Dblock]

I think the h-dev decats have spacers built in I'm sure.

[DoogyRev]

I think the h-dev decats have spacers built in I'm sure.

 

I think your right

[veilside z]

my cel light came on after my decats and got spacers from zmanalex off this forum (thanks again alex) and this cured the problem.

[spursmaddave]

Yeah if you don't get the ones fitted with spacers they are not very expensive from Zman Or just get an upRev and get the CEL sorted for good

[Geldy]

on my road cars i have allways gone for sports cats easer when mots and stuff come around and new cars dont like de cats as much

[stillracing]

Having bought de-cats recently and been concerned with the possibility of running lean, I did some thinking back to my engines lectures at uni. I realised that the ECU only uses closed-loop mode (ie. adjusting fuelling based on lambda values) during steady-speed and thottle-closed events. As soon as you plant it, the ECU switches to open-loop mode to give safe acceleration enrichment and therefore uses the Nissan-set map. Hence the air-fuel ratio does not depend on the O2 sensors during hard driving.

 

So I would say that you're safe from that point of view. This is assuming that damage won't occur from slightly lean running during closed-loop running. Hopefully it's just a case of preventing the pesky CEL coming on

[Neilp]

Having bought de-cats recently and been concerned with the possibility of running lean, I did some thinking back to my engines lectures at uni. I realised that the ECU only uses closed-loop mode (ie. adjusting fuelling based on lambda values) during steady-speed and thottle-closed events. As soon as you plant it, the ECU switches to open-loop mode to give safe acceleration enrichment and therefore uses the Nissan-set map. Hence the air-fuel ratio does not depend on the O2 sensors during hard driving.

 

So I would say that you're safe from that point of view. This is assuming that damage won't occur from slightly lean running during closed-loop running. Hopefully it's just a case of preventing the pesky CEL coming on

its been checked on the dyno and these cars do run lean on full throttle and part throttle with decats without a map....