Jorge Vazquez

I had to take apart my 2009 A4 Quattro to replace the injectors. While I was at it, I changed the oil and the oil filter. Unfortunately, I did not put the tube that goes in the oil filter receptacle back in. When I started the car I was getting a low oil pressure warning and an implausible MAF signal code. But the engine was running smooth as silk. Not knowing that it was just that little tube that was causing the problem, I changed the oil pressure sender and the MAF. The MAF code gone, but low pressure still shown. I finally found the answer to the oil pressure problem and ordered a replacement tube. I started the car, but now, it was no longer running smooth. In fact, it was not running at all. I could not get the engine to start. Crank yes, start no. The codes showed misfire on 1, 2, 3, and 4 and also the random misfire code. WTH did I do? I checked all the wires, everything is seated properly and all connectors are connected. I ordered a set of coils and a set of spark plugs. Changed them both. Put the car back together, and now I get misfire on 1 and 4. I've swapped the coils with 2 and 3 but the misfire does not follow the coil. The engine starts, it's just a hot mess that barely stays running. Another thing I tried is to pull the connector from coil number 1- doing so does not have any effect on how the engine is (barely) running. Plug it back in. No difference. Could the wiring have gone bad somehow?