172 Cup Failed Emissions... Badly

[GryphusOne]

Following up on my previous post (https://cliosport.net/threads/172-cup-massively-over-fuelling.850820/) I thought I'd check if you had any other ideas about what could be causing my emissions problems before getting it remapped. As you can see it failed on everything! I know it needed a new cat last year to get through the MoT before I bought it, so I'm expected it's got a cheap ebay special on it. But just a bad cat wouldn't cause the hydrocarbons to be that high? And similarly I don't think a bad map would cause the CO to be that bad unless I'm mistaken?

Occasionally my emissions light comes on, however only if the car is sat idling for a ~1 minute when it hasn't fully warmed up.

Thanks

 

[Matt Cup]

Could an inlet gasket/seal leak cause emissions problems?

 

[GryphusOne]

Could an inlet gasket/seal leak cause emissions problems?

Certainly could, still wouldn't explain the hydrocarbons though I don't think (Although I realised I didn't upload the results so here they are)

 

[Matt Cup]

Was only wondering as I had took mine to Mick @Diamonds to be checked over and he said I had leaks from both upper and lower inlet manifolds and also the map and air temp sensors which the ECU was just about managing to keep within range.

I know very little about engines and emissions though.

 

[R3k1355]

I ran a cheap eBay cat through five MOT's without issue.

Clio's are well known for dodgy lambda sensors, I'd start there, and maybe do the coolant temp sensor while you're at it.

 

[GryphusOne]

I ran a cheap eBay cat through five MOT's without issue.

Clio's are well known for dodgy lambda sensors, I'd start there, and maybe do the coolant temp sensor while you're at it.

Thanks, will look into it. Was that a 200 cell cat? I'm sure a 400 cell cat could get through MoT's but don't wanna be losing power!

 

[Louis]

Thanks, will look into it. Was that a 200 cell cat? I'm sure a 400 cell cat could get through MoT's but don't wanna be losing power!

172s are 400cell as standard anyway. You won't lose power.

I reckon you've exhaust leaks

 

[GryphusOne]

172s are 400cell as standard anyway. You won't lose power.

I reckon you've exhaust leaks

Ah that's news to me, I thought they were 200cell, yes I've had a few issues in the past year with exhaust leaks, twice I've had an exhaust hanger fail on me so I'll get in the air and have a look myself rather than trusting the garage! Would an exhaust leak cause the high hydrocarbons? I assumed that would be due to fuelling and possibly injectors.

 

[R3k1355]

Would an exhaust leak cause the high hydrocarbons? I assumed that would be due to fuelling and possibly injectors.

Might depend on where it's leaking, but you'd have an exhaust leak listed as a fail surely?

Injectors do fail, usually send the car to limp mode. Lambda's fail all the time

 

[Robbie Corbett]

My car ran very rich when I had a failing primary lambda, took ages for it to give a fault light, then a few months later a failing injector did exactly the same thing, car super rich, would intermittently light CEL but not always.

Id say start with injectors and lambda - these are both very common failures on 172/182's

 

[GryphusOne]

My car ran very rich when I had a failing primary lambda, took ages for it to give a fault light, then a few months later a failing injector did exactly the same thing, car super rich, would intermittently light CEL but not always.

Id say start with injectors and lambda - these are both very common failures on 172/182's

Perfect, will get those sorted asap. Thanks for the help.

 

[Robbie Corbett]

No worries. Worth mentioning that it took a fair while for mine to run any different when I had a failing injector. While the lambda made the car run like s**t.

 

[GryphusOne]

Fair, mine is still running fine but it'll probably be easier to just do both at the the same time!