chocolate_o_brian

iTrader: (22)

bit of a debate going on in the thread i started about a possible failing m.a.f. sensor on my my99 uk classic turbo.

ive recently had the centre decat and backbox "finished" off with the decat downpipe. i have been told that unless i remap the ecu, the car will run lean and will cause serious damage to the engine.

im just looking for opnions on this, as i was looking to remap the engine, when i have any other supporting mods ready to go on.

who else has a decat-ed classic scoob on here without a remap, and who's engine hasnt blown up.

looking for opinions as im quite confused as of now, from differing opnions after my maf (possible) problems.

Britishdaddy

good question as i have a wrx import wagon my95 and i put a full decat 3" exhaust on, a apexi race air intake,a manual boost controller, and it ran perfect not over fueling or anything UNTIL i changed the fuel pump for a 255lph uprated when i put it back together i had nothing it was trying to kick over but pump wasnt priming since then i have tryed everthing poss but now i have to test the crank shaft sensor and if its not that then i might break it buy a mini and put the straight 4 lump in it(non turbo) i will sell the turbo and IC etc but thats just a dream at moment good luck with the modding Dan

fireblade37

iTrader: (1)

Ran my00 for two years with a full decat green pannel filter, no probs at all

raw1879

hi there your car needs to be pluged into a select moniter

scoobykev1

I have a my99 with de-cat exhaust and no re-map and runs absolutely spot-on. BUT.... im on my 3rd MAF this year!!! to be honest your problems dont seem the same as what i had. When the last 2 maf's have gone wrong ive been driving the car quite hard! about 5000revs and the engine sputters and dies! i pull over and try starting back up. starts then dies- starts then dies etc. after about the 3rd/4th restart it idle's fine but my CHECK ENGINE light stays on. Cant drive over 2500revs or the car just sputters and misfires (cant use turbo).

Ive had these exact same symptoms twice and its turned out to be the maf.
Car is near on standard and even running a panel filter so i dont know why my maf keeps failing

Cost me about £90 a pop

chocolate_o_brian

iTrader: (22)

lol dont really use my car that hard, only a blast now and again. just about to go to work, and will see what happens.

Wurzel

iTrader: (1)

Ran my MY00 classic for years decatted before I got a remap with no probs at all.

funkyspider

The only way to tell if you need a remap is to check the AFR really, so if in doubt then get it plugged in and see what they are and what the ECU is up to. Some people report overboost when decatting, others don't. So I guess every car is slightly different - what worked for someone else may not for you.

I suppose another question is with the MAF reportedly being weaker on 99/00 is running a decat system going to magnify any problems if the MAF does start to fail.

To put it another way, its the cost of checking it, against the cost of sorting out the engine should anything happen.

The Chief

A good friend of mine who really knows his stuff (3rd in recent Scooby Shootout) told me a lot of people run decats without issues but.... strongly advised me to have mine remapped when i had this.

A remap makes a big difference on the road and a reputable mapper like Andy Forrest will make your car safer too.

get it done

TonyG

Had a decat downpipe on a MY00 for about 4 years without a remap. Now got a sports cat on. Engine ran fine with no problems

scoobyDAZZA

it will be ok but it would be better if it was mapped
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scooby350bhp

got a 3 inch de cat on my 97 with no probs

New_scooby_04

iTrader: (4)

Not sure about your Maf mate, have you done any mods that might introduce more vibration/possible contamination into the MAF? They're very fragile on MY99s.

As for the decat, general concensus -and my experience- is that a UK MY99 non-Sti will run one without issue on SUL fuel. I got a knocklink when I decatted mine, just to be safe prior to the additional mods and remap. It never showed more than two greens (better safe than sorry though).

Ns04

Dark Blue Mark

On a UK MY99 a full decat and no remap should be fine, but get it dyno'd to be safe. Bonus of a remap is it will correct your fuelling, but also give you more power from increase in boost and ignition timing.

I certainly wouldnt advise runnind any JDM car with a full decat and no remap...

trails

iTrader: (41)

ditto

Tidgy

should be ok, some cars don't seem to like it though, not sure y. just some do and some don't adn get overboost issues.

chocolate_o_brian

iTrader: (22)

just posted an update on the other thread about my problems...

https://www.scoobynet.com/scoobynet-...ml#post7063341