Technical Can anyone help me with emissions problem?

[melcat]

Hi everyone,

Got a problem with emissions. MOT failure.

Here are the readings.

Natural Idle test CO emissions shoot up to 10%

Fast Idle test CO emissions in limit at 0.27%

Whats going on here?

The garage want to put a new CAT on it at £260.00. When I said its OK at fast Idle it's not the CAT that needs replacing. They couldn't answer it.

I have changed the coolant temp sensor and cleaned out the throttle body along with the air sensor too. checked for leaks in and out of the engine.

I have reset the ECU and give it a good hiding with REDEX in the tank.

It's my sons first car and can't get to the bottom of this problem.

Where do I go next?

Mel

 

[Ffoxy]

Hi everyone,

Got a problem with emissions. MOT failure.

Here are the readings.

Natural Idle test CO emissions shoot up to 10%

Fast Idle test CO emissions in limit at 0.27%

Whats going on here?

The garage want to put a new CAT on it at £260.00. When I said its OK at fast Idle it's not the CAT that needs replacing. They couldn't answer it.

I have changed the coolant temp sensor and cleaned out the throttle body along with the air sensor too. checked for leaks in and out of the engine.

I have reset the ECU and give it a good hiding with REDEX in the tank.

It's my sons first car and can't get to the bottom of this problem.

Where do I go next?

Mel

Air filter nice & new? If so maybe the lambda sensor in the exhaust manifold...? They normally throw up an error code though.

Clean new oil and spark plugs can help too.

 

[melcat]

My boys car has only done 42,000 miles and on a 1998 plate.

Car had only done about 160miles since its last MOT the rear seat belts were still done up.

Oil and air filter is clean.

Being unused has not done it any favours.

Spark plugs and HT leads may be next, maybe Lamda too?

 

[Ffoxy]

My boys car has only done 42,000 miles and on a 1998 plate.

Car had only done about 160miles since its last MOT the rear seat belts were still done up.

Oil and air filter is clean.

Being unused has not done it any favours.

Spark plugs and HT leads may be next, maybe Lamda too?

OK and maybe a good "at the limit" long blast on the motorway so the injector cleaner gets a chance to shake off any crud.

 

[Oldschool]

Air filter nice & new? If so maybe the lambda sensor in the exhaust manifold...? They normally throw up an error code though.

Clean new oil and spark plugs can help too.

As Ffoxy said.

 

[melcat]

Here's the latest update.

New plugs fitted, the old ones looked tired.

Car gone in for diadnostic check.
Diagnostics had some error codes and now have been cleared.

No more error codes come up. When ran again.
CO emissions still at 10% on natural Idle.
And works fine at fast idle.

Ok here we go, having a new lambda probe fitted now.

Don't where to go next after this.

See what happens.

Mel

 

[Ffoxy]

Here's the latest update.

New plugs fitted, the old ones looked tired.

Car gone in for diadnostic check.
Diagnostics had some error codes and now have been cleared.

No more error codes come up. When ran again.
CO emissions still at 10% on natural Idle.
And works fine at fast idle.

Ok here we go, having a new lambda probe fitted now.

Don't where to go next after this.

See what happens.

Mel

The Codes stored would have been very useful Mel....

 

[melcat]

Well, well, well!

It isn't the lambda probe.

There was an error code for the throttle potentiometer. but when cleared it didn't return.

Problem is you need to replace the whole throttle body. What a bummer.

I post a new thread for this.

Mel