Looking for some advice from one of the many techies we have on this site.

I have a 1.6 TDCi Feb 2008. 118K on clock. DPF removed and remapped. EGR Blanking plate fitted (Polish supplier on Ebay). Recon Injectors fitted. Cam belt replaced.

Occasionally when accelerating in 4th/5th there is a slight juddering, as if the timing is not quite right. If this has occured then I'll experience thin white smoke when I lift off the pedal and this will continue intermittently for the rest of my journey. If the juddering hasn't occured then neither will the white smoke.

Someone ( a commercial vehicle mechanic ) suggested over fuelling, could this be and if so what is the remedy ? The car is not doing a great deal of motorway mileage at the moment and isn't being very fuel efficient which made me wonder about this last point.

I'm also getting a bit of engine/diesel odour coming in the air vents. I've checked the injectors and whilst I've suffered injector leakage in the past, there's no evidence of it now. no "pfut-pfut-pfut" and no detectable exhaust blowing up from the injectors.

Could this be related to a split or broken pipe somewhere around the engine ? If so what other symptoms might I experience, in relation to the existing ones.

Have you checked your boost pipes for any splits or leak in boost, at what rpm does this happen as I know mine doesn't like sitting below 2000 rpm in any gear and the remap that's been done has it been done by a company that knows what they are doing, I have had cars in past that's had a cheap map and caused no end of problems was it a file map or a map for your vehicle?

When the injectors were replaced, the guy doing it had difficulty in getting the new codes to save. He had to borrow another garage's computer kit, which apparently was a better piece of kit, and then having taken advice from them did some kind of factory reset in order to complete the process.

I did wonder if this might have reset something else which was now causing me some problems.

It sounds like the coding is wrong for the injectors, especially given that they didnt save. They may be the same injectors, but they would need to be relocated to exactly the same place, and also because of the recon would probably need coding again, more than likely a change to the timing would have been necessary.

The car has just been MOT'd and serviced.

The smell turned out to be loose connections on the injector fuel pipes, sorted.

The white smoke is still there occassionally. Usually first thing in the morning or whenever the car has been standing for a while.

New regulations coming into effect from 16th Feb mean that any car which comes with a Catalyst or DPF as standard must be fitted with them or it automatically fails it's MOT. Looks like that'll be the next be purchase.

the white smoke will just be condensation in the exhaust, the cold means that the water vapour will cool to water droplets. These evaporate to steam and appear white when pushed out the exhaust.