PRE CAT QUESTION

[s3c chris]

Hi.
I had my car mot’d today and thankfully all was well apart from headlamp aim and a very high CO reading.
I wasn’t present at last years MOT ( at a different garage) and I assumed all was well.
This year however the CO reading was well over 3.0 instead of 0.3.
My car is a year 2000 500 and the exhaust is standard although the pre cats have been removed as one was rattling.
The trip to the MOT station was the first run for a few months and I did go the “long way round” to get the car warm and it seemed to drive normally with no problems.
Any help would be appreciated.

Many thanks, Chris.

[QBee]

IIRC precats are only there to keep emissions within limits when the engine is cold/cool.
I had a lower reading than you on my fully decatted car, so I suspect your cat may have died.
Time for a trip to the Blue Cross for a new one?

In all seriousness, complete exhaust systems do come up for sale from time to time and aren't expensive.

[s3c chris]

Thank you for the reply.

I doubt a trip to the Blye Cross would help as I am partially allergic to cats. That must explain the problem with the car!
I was wondering if a failed Lambda sensor would cause the problem? I am afraid I don’t know much about “modern” electronics but have read that they can cause high emissions when they have failed. Is there any way of testing these?

Regards Chris.

[QBee]

I suspect that in the right hands RoverGauge would tell you if the lambdas were performing correctly.
It's free software, you just need to buy the computer lead from Blitzracing on here. I have a feeling it is advertised in Parts in the "Buy" section under TVR.
Hopefully the usual suspects, including Blitz himself, might be a long in a while to advise.

[sapper]

A similar thing happened to me years ago, the connection to the air flow meter was loose..
Might be worth checking as it’s not obvious at first glance.

[LLantrisant]

had similar readings with my 400....1lambda probe was shot....new probe....CO within limits....just to mention: car passed MOT and related emission test just a few miles before.....but that few miles where nearly 1y b4 my onwership....
also my car has pre-cat´s removed...thy are just for emissions after cold-start.

old fuel, long time not driven, injector cleaner...all bla, bla...such high readings have a "real" technical fault as background

Edited by LLantrisant on Thursday 7th March 20:42

[s3c chris]

Thank you for the replies.

I’m hopefully going to get the sensors tested tomorrow and if that proves inconclusive I’ll get a rovergauge lead.
Incidentally, when starting from cold it is quite a while before the initial “missing” clears and after that it runs fine.

Regards Chris.

[s3c chris]

Hi.

Thank you for the replies. Just to say that after testing the lambda sensors using Rovergauge, it was confirmed that the even sensor on the drivers side was indeed faulty.
Fitting a good used one appears to have solved the problem for now, fingers crossed!
After seeing Rovergauge in action I will definitely get one ordered....

Regards Chris.

[Steve_D]

s3c chris said:

...................After seeing Rovergauge in action I will definitely get one ordered.....

Best tool an RV8 owner can get and only £35.

Steve