Emissions fail - have exhaust leaks

[mikehammer69]

Hi
My car (99colt) failed on emissions and has a couple of exhaust leaks

Is it possible the exhaust leaks could cause the high CO( 7.24% high idle) and HC( 1546ppm high idle) or will it definitely need more work

Thanks

 

[Burnerman]

I would say its rather unlikely, but the exhaust needs to be pretty sound anyway for accurate analysis - although tiny blows are acceptable.
What did the test centre say?
John

 

[Belle427]

I do not see minor leaks causing those readings, it looks as if you have a very rich fuel mixture maybe even a misfire?
A lot of things can influence this, when is the last time the engine had a full service?

 

[Sylvesterrrr]

Try connect VCI diagnostic tool. it's tell you everthing

 

[Belle427]

Try connect VCI diagnostic tool. it's tell you everthing

No it wont.

 

[Burnerman]

I'd go for a new air filter and a service first!
John

 

[mikehammer69]

Sorry for the delay replying
The car is well serviced re: plugs oil filters

My thinking is there will still be a sensor issue after the exhaust is repaired

AFAIK exhaust leaks won't cause high CO and HC only lambda

 

[Burnerman]

How does the car behave generally.....does it pick up well, have a tendency to stall at traffic lights, uneven tickover or whatever?
Is the engine management lamp on at all?
John

 

[mikehammer69]

No lights no stalling etc
Runs perfectly as far as I can tell

 

[Belle427]

You will need to check out things like lambda sensor switching if it has them, not easy for a diyer especially if the car has an older diagnostics port.

 

[mikehammer69]

I figure lambda sensor is the most likely cause

 

[Sylvesterrrr]

I'd go for a new air filter and a service first!
John

Is not worth to do service, before fixing the problem

 

[mikehammer69]

repaired exhaust and changed plugs-she passed no problem today
car is always well serviced

 

[Burnerman]

Excellent! Many thanks for the update. Its very important for cars with minimal pass emissions to get the cat stinking hot - maybe that helped too.
John

 

[mikehammer69]

I drove it like a maniac before the test, 93 degrees for test
I threw in 10L of alcalyte petrol into an almost empty tank for test. I hear people are getting very low readings with this fuel

Co was 0.01,HC 18PPM