Rover 200 & 400 Owners Club

I have had real trouble getting my 214 SEi through the MOT due to emissions. It eventually passed this afternoon but only just.

The car has 55,000 on the clock and is in good mechanical order with no faults.

In December 2020 at 49,000 I had a full stainless steel exhaust fitted. Since then I have done 6,000 miles. I have had no emissions problems in the past.

It failed on the emissions and the main problem area was CO on fast idle. Lambda reading were not great either. Car was tested whist hot.

The MOT tester suspected a "cheap cat" and recommended I take it back to the specialist exchaust centre. I did this and they swapped the cat at cost price, unfortunately this made no difference.

I then had the Lambda sensor swapped - this resolved the Lambda readings, but not the fast idle CO.

Struggling for ideas, I had a look round on the forums and discovered a few posts about the lambda sensor relay. I opened up the fuse box under the bonnet and found 5 fuses and an empty slot. It appeared the lambda sensor relay was MISSING (I don't know if is normal for this not to be present). I found one in my spares box and fitted it in the empty slot. However this didn't make any different and it still failed the re-rest.

Finally he gave it another go, and the emissions test passed (only just) but I don't want to go through this rigmarole every year.

The tester still thinks the problem is a "cheap cat" and that a better quality cat would resolve.

What are people's thoughts? What would be the things to look at for a high CO reading at fast idle?

Have you tried the old trick of putting in some super-unleaded and taking it for a hard run on the motorway before the test. Could it be a bit coked-up?

g259fsg wrote: ↑Fri Jul 05, 2024 4:03 pm Have you tried the old trick of putting in some super-unleaded and taking it for a hard run on the motorway before the test. Could it be a bit coked-up?

Yes, before the first test I'd blasted it at 70 down the local A road. And I only ever use Shell V Power fuel.

I have had 'difficult' emissions tests in the past on K-series cars and also on the T-series.

Check that your air filter is in good clean condition.

Also check if there are any slight leaks on any of the joints in the exhaust system: under certain running conditions, these can interfere with the operation of the catalyst.

Finally, there is still a possibility that a low grade catalyst could cause a problem, because the R8 does not have a 'downstream' Lambda sensor the ECU cannot monitor the output from the catalyst and make any adjustments to suit. What happened to the original one?

I have a print-out of an 'MOT Emissions Test' from August 2002.
When all cars being tested were either Euro1 or Euro2 emissions standard.
The 'Fast Idle' CO limit was 0.3%,
and 'Natural Idle' CO limit was 0.5%.

With the advent of Euro3 or Euro4 emissions standards,
The MOT Emissions Test became more stringent.
The 'Fast Idle' CO limit became 0.2%,
and 'Natural Idle' CO limit became 0.3%.
The test equipment was set to these new default limits.
The MOT procedure was to initially test all cars at these new default limits.
and then switch to the old limits if required for Euro1 and Euro2 cars.
However, this was rarely done, as Euro1 and Euro2 cars would mostly pass the new limits.
As I understand it, the old limits still apply for Euro1 and Euro2 cars.

Good point. I wondered about that too. I think there is a similar variation on brake efficiency.

220 GSi turbo wrote: ↑Fri Jul 05, 2024 9:24 pm I have had 'difficult' emissions tests in the past on K-series cars and also on the T-series.

Check that your air filter is in good clean condition.

Also check if there are any slight leaks on any of the joints in the exhaust system: under certain running conditions, these can interfere with the operation of the catalyst.

Finally, there is still a possibility that a low grade catalyst could cause a problem, because the R8 does not have a 'downstream' Lambda sensor the ECU cannot monitor the output from the catalyst and make any adjustments to suit. What happened to the original one?

The air filter is a K&N panel filter, but wondering if I should try a standard paper filter next year.

I know I have a bolt missing from the exhaust manifold, but this has been missing for some time - the original bolt had got “threaded” at Rover Revival and I’ve never got round to having it replaced. I’ll sort this as well.

The original cat was left with the exhaust centre 4 years ago and will have been scrapped now. It never occurred to me to ask to keep it.

Easy way to check the Cat is with a laser temperature gun, hold the engine at fast idle the temperature at the back of the Cat should be around 40 degrees hotter than the front

JOHNDQ wrote: ↑Sat Jul 06, 2024 10:08 pm Easy way to check the Cat is with a laser temperature gun, hold the engine at fast idle the temperature at the back of the Cat should be around 40 degrees hotter than the front

Good tip, thank you.