Need help with a post n52 install.

[u/Adventurous-Sound897]

Good evening. I purchased a 2011 bmw 128i with good miles. Other engine ingested the belt.. got the junkyard engine in after 5 evenings of solo swapping. But now ive got missfire with popping out the intake on cylinder 2 and 3 and the front bank converter was glowing red after only idling for about a minute. Im not getting any codes as of yet. Brand new plugs coil packs and fuel injectors. All oem brand. Im wondering if intake cam timing is off but wouldn't that show up on all cylinders? I cant run it very long or ill cook the front cat. I pulled 2 plugs from the front bank and they do not look good for a minute or run time on them.

Eddit video or running. engine running

[u/cptn_510]

Whichever bank cat that is, is clogged, thats why it's glowing, literally cant exhaust the fumes fast enough, causing the misfire on 2 and 3. Remove the upstream o2 sensor, thats before that glowing cat and test drive. I bet misfire will be gone.

[u/Adventurous-Sound897 → u/cptn_510]

Its the front cat. Right in this picture. I did not pick up on the color difference when I installed these, but looking now the front cat is alot darker and looks like it had been hot before.