Ben123456789

Just had the car fail the MOT on emissions It has a decat pipe but the garage fitted a standard exhaust (with two cats) prior to the MOT. This setup worked fine last year and it passed with flying colours.

The garage think that the CO reading is too high to be just a sensor and that it is likely to be a problem with the ECU map. It is a Link ECU (first generation). They said that the ECU mapping can sometimes develop problems over time with this type of ECU.

Before we get a mapper in to look at it, is there anything else that is worth trying? Can a faulty O2 / MAF sensor definitely be ruled out?

In case it is relevant, there is also a starting problem which began to manifest last winter, it stalls immediately after it first fires up (the revs just drop out) unless I blip the throttle gently just before it cuts out. This only happens when cold.

Any advice would be much appreciated.

It's a MY97 turbo 2000 with various mods (VF28, STI intercooler, uprated fuel pump, injectors)

Glowplug

iTrader: (8)

Lambda and or coolent temp sensor.

I know **** about mapping so i'm probably miles off.

Jolly Green Monster

iTrader: (4)

Link ecu g1 very little chance of passing the emissions test, the closed loop lambda fuellong required to pass is very slow to reach and usually doesnt work.
However you are saying it def passed like this before?

What is lambda reading?

The link doesnt use maf sensor

If it is a sensor then the lambda sensor

Simon

JohnD

iTrader: (5)

When I had a Link ECU (Supplied and mapped by Bob Rawle) in my 99my I had to refit the original board at MOT time. No chance with the Link fitted.

JohnD

Jolly Green Monster

iTrader: (4)

Very common

Ben123456789

JGM, thanks for the response. It passed last year at the same MOT garage with the same setup, I've done nothing to it since (engine wise anyway). Do you have any idea why it would have done this in the space of a year? I was under the impression that once a map is written, it can only be changed by remapping (with the exception of changing the ignition firing angle).

John D, unfortunately sticking a standard ECU in for the MOT is not an option on mine as it has bigger injectors (from an STi I think). Nice idea though.

The mapper is going to look at it tomorrow morning to see if it can be tweaked to pass. Fingers crossed, I will update with results. Any other comments in the meantime would be appreciated, as always.

Ben123456789

It has passed It was the mapping, they were able to make some temporary adjustments to get it to pass. It is still a mystery why it passed last year and not this year.

I might look into replacing the Link with a Simtec ECU next year.

Jolly Green Monster

iTrader: (4)

Well done

I expect they altered it using another car on the emissions machine

Simon