NCT Query - Smoke

Car would be completely down on power and would be really hard to rev out while driving.

My money is on an intercooler pipe. Had a 508 failing the emissions a few months ago.

No black smoke, wasn't down on power. Tried diptane, HVO, driving it for an hour before

the test and still no joy. Tried this method twice. It actually went up on the second attempt.

Turned out a small hole in an intercooler pipe. Changed the pipe, put more

diptane and HVO in for good measure and it sailed through. Went from 1.7 to 0.12.

DPF had been removed from this car too. Not sure if it had a remap but FC uk this car

was quick. Standard it made 150bhp but I think it was up over 170.

If it is a small hole, he might not see it. I didn't when the 508 I had was failing on emissions.

I only seen it after I was replacing a leaking water hose. Only way to know for sure if it is a

leaking intercooler/boost pipe is to take them off and inspect them and that can be time consuming.

All you can do now is run it through again. But make to use diptane and HVO this time.

Make sure you let us know how you get on.

You and another idiotic poster are just assuming they have deleted the DPF. Driving a diesel car hard before the test can most certainly get rid of excess smoke

If still had dpf it would be blocked solid with smoke reading like that

The OP stated that the car failed on smoke/emissions. The OP also said that the car is used mainly for short journeys. Your Prof Pat pending advise is that the OP should rev the guts out of the car for a prolonged period. That won’t do anything only waste fuel and or blow the head gasket. It was also suggested at one stage that driving at 120kph in 3rd gear will fix the problem, ok right but what happens when the clutch or gear box gives out. Regarding the DPF I merely said deleting them is illegal. Why don’t you take your opinions and stuff them up your arse, assuming you can get off the armchair.

Revving an engine for a few seconds is not going to cause any damage to the engine. Thats what rev limiters are for. I didn't suggest to drive at 120 in 3rd gear. Thats probably not even possible in most cars. But in any case driving the car hard and to the red line isn't going to cause any damage to the car, especially not the clutch or gearbox. Its been well documented on here and elsewhere that driving a diesel car hard after a failed smoke test can result in a pass if the car hasn't been driven hard in a while.

Real world example any time I drove my Dads transit it will billow out smoke from the exhaust since he never drove it hard enough. He failed his DOE and subsequently passed his retest after I gave it a hard drive for a few minutes.

And who saying there isn't no one. Just saying vehicle with dpf working won't fail smoke test

It doesn’t, but a common reason why the DPF is removed in the first instance is because the engine was smoky and blocking the filter.