Hoping someone can help me. I have a Fabia 2 Monte Carlo 105 Cayc. It has just had a replacement engine with the turbo refurbished, complete set of new injectors all coded accordingly, a dark side EGR delete kit and the DPF gutted. Started the car and obviously had the EGR fault as it has been totally removed and low fuel pressure as I had to bleed the fuel system. Once running and faults cleared the only fault that remained was the EGR and the car was in limp mode with EML on, other than that it ran sweet. Got mobile remap guy to carry out the EGR and DPF delete and the EML was gone but there was a bad diesel knock after. Remap guy told me it was injectors these have been sent back and tested and have come back with no faults. Car has now been towed to another tuning garage as couldn’t get back in touch with mobile guy and they have put back to standard and it is still knocking, but apparently there is an intermittent ECU non communication fault. Has anyone got any ideas?

My money is on the EGR delete not being coded properly by the mobile tuner, esp if he was quick to blame the injectors without saying why, and dodging you trying to make more contact.

Putting the map back to standard with the egr and dpf deleted the eco is going to be having a fit trying to figure out why it’s running weird and the sensor information isn’t as it should be so will be doing all kinds of weird fuel/air adjustment trying to make the flow values make sense to itself.

Needs to be coded out properly and tested, by someone who knows what they are doing.

I had an egr delete (dpf still there) done in Jan on the same cayc 105 engine in my octy and I have had no problems with it since it was done 🤷🏻‍♂️

Thanks, the place the car is at now they have been recommend as they know what they are doing and with the intermittent ECU fault they are recommending a replacement ECU and starting again.

Ah fair enough, I missed the intermittent ecu fault. That could cause any mapping to get corrupted during the updates.

But that could also be corrosion in the pins or a wire break in the loom to it.

I assume they have pulled the ecu and tested it on a known good loom?

Not sure think they are only going with the diagnostic machine report

Be worth asking them that question before shelling out for an exit it might not need…

Just got work back they are saying that I cannot get a replacement ECU from eBay for example it has to come from skoda itself and be programmed to car. Latest advise is to remove ECU and send for testing and been advised to use ECU testing. Any advised at this stage?

Little update I Have the car back with ECU rebuit as it had intermittent fault car still has knock rattle at cylinder 3. Wiring loom has been check and I have no broken wires in loom from ecu to injectors.

I did remove injector 3 and noticed it was still like new as if no fuel had been burnt and put a 2nd hand one in known to be good as it had been tested still same. But still same knock/rattle. I used a stethoscope and listened to each injector all sound the same.

I have now removed all injectors and 1,2,4 are used looking and 3 is clean this can see in picture attached.

Removed rocker cover and nothing jumping out as no filings etc and I have read that this engine is prone to top end wear although I have circled and inlet and exhaust lobes on cylinder 3 as these 2 lobes are slightly different colour.

there is no smoke from car as it’s really only ticking over oil still clean etc and no sign of fuel mixing into oil as I would expect that if there was a ring problem.

Just don’t know how much further to go here.