Can anyboby help me, went for a mot. All was fine till it was time for the co level bit. it only seems to go downs to 5.5 ish. But just keeps on creeping back up to about 8.5 ish its a stage 3 greens etc etc whats the likely cause of this?. Is there any way of getting it down just for the mot, cause my local tuner is fully booked to november

 

shitty off the shelf chip

whats your map sensor reading at idle?

dont supose by any chance yuove got a secs monitor?

also you say it goes to 5.5ish, is that when you turn down the adjuster screw, or have you not touched the screw?

 

I aint got aclue what the map sensor is reading, tho it is a new one. yes it goes down when we turned the screw. then just creeps back up

 

what chip is in there?

did it used to work ok?

 

the chip is a ahmed bayjo one i belive, has been fine as far as i know. well maybe alittle rich

 

as far as you know?

have you not put the car thru an MOT before?

if you knew then you can guess at if its a sensor fault, or if your chip is just shit

those ahmend chips run barely MOT passable CO as it is... but 5% - 8.5% is a LOT!

 

ok sorry yes it was fine last mot all sensors are new

 

ok then you have a fault...

either:

dodgy wiring
vac leak
Coolant Temp Sensor (which reminds me, was car warm when they tested it?)
ACT Sensor
wrong Fuel Pressure
fooked injectors
Map Sensor

 

hmmm i was going to say either the act or cts sensor when were they new as you could have buggerd one?

the sensors are basically big resistors, when the car is warm they give little resistance so the ecu then cuts the fuel back.

there is a way that i used to test them but not sure if its a good idea or not as it tended to blow the 30amp fuse found near the ecu

it will tell ya if the sensor is working though

warm the car up and unplug the sensor, on the plug, bridge the 2 contacts with a bit of wire. this will give the ecu the same low resistance signal that it would normally get if the sensor is ok

if when you do this the co comes down to normal then you have a bad sensor

or like jim says it could be a split vac pipe

 

ok cheers for help, I think i'll leave it in the garage for a month. Or it will end in tears pmsl

 

wharrrrt?!?!

that an't no test, that asking for trouble IMO!

 

well it worked for me only did it for 10 secs and didnt do any harm told me what i needed to know anyway

by all means if ya wana go waste the £30 on the sensor without knowing if you need it then be my geust!

 

Buy a multimeter and check the resistances from the main ECU plug is easiest

Look on here for resistances:
http://www.homepages.hetnet.nl/~pete...ick_check.html

Easy job