Hi guys Been posting a few times about problems with my Car and I've been given loads of advice by people and I've tried it all and still my Car isn't sorted, problem is the Cars running like a bag of ****, I replaced the engine because my last one seized, along with that I had a de-cat, Honda S2000 air filter and a universal FMIC fitted, since then the Cars just ran terrible, at first it was ok and then it progressed on only happening after an hour or 2 of driving, we plugged it into diagnostics and nothing is coming up everything's running perfectly fine or atleast the system thinks it is... So we replaced the spark plugs and that actually solved the problem for a couple of weeks then it came back and eventually the problems just got progressively worse. We've swapped parts over from the old engine to try an fault find basically all the sensors have been swapped about apart from the MAF as that's showing up fine on the system. I recently bought new sparks in a hope it was just them again and nothing changed as expected. Anyway made these videos and took some pics to try and help. 99 Plate Audi A3 problems - YouTube 99 plate Audi A3 exhaust problems - YouTube New sparks Removed old spark New spark after being in engine 3 minutes All the sparks were all covered in black ****ty dust, and the 4th plug wouldn't screw in properly when I was tightening it it felt like it was cross threading or something was in the way, I attempted it 4 or 5 times but each time went in strange, the plug was straight and tightened up as normal it was just the process of screwing it in that felt odd. Anyway I'm at a complete loss the mechanic I always use says it needs a remap and the ECU needs taking out for it, he's pretty dead cert on it being that actually. What are your thoughts?