So I thought I was on to something with the new lambda sensor. I drove the car around and while better it still wasn't perfect. But then it hasn't really been since I've had it.

Anyway, put it in the garage last night. Was warm from earlier so in to closed loop fairly quickly. Window down to fold the mirror in and I can hear the chuffing and fluttering noise down the exhaust again.

For reference three coils are newish Diamond. Three are brand new SNG unlabelled. Injectors cleaned. New spark plugs - SNG EBC11480*. Not sure what brand they sent. New stat. New crank sensor. Recent Bosch battery, fully charged. Brand new manifolds. One new and one recent lambda sensor.

I guess MAF is an obvious thing to check next when I get a few minutes. Someone suggested a vacuum gauge might be illuminating too.

It sometimes makes a noise like an grumpy bear on cold start but I'm guessing that's just the tensioner needs changing?

We'll get there in the end!

 

Hrmm, was going to suggest checking for exhaust manifold cracks, but sounds like you have that covered.

You think you might have some other exhaust leak or maybe even a clogged catalytic converter?

The "chuffing and fluttering noise down the exhaust" has me wondering about the exhaust part of the equation.

.

 

Good news. Nothing wrong with the connectors on my ecu, which is one cause of poor idle ruled out.

Bad news. 90 minutes of my life lost, most of it spent upside down in the foot well. Bloody security screws.