Hey guys I just did a tune up on my 03 max and ended up needing a new rear valve cover due to oil leaking in one of the back plugs. So I put all new plugs ( NGK Iridiums ) and new rear valve cover.

I now have a rough running car and the codes P0300 Random multiple cylinder misfire and p1614 NATS Malfunction.

Just a small note to consider is that the plug that had oil in had for a decent time and the coil was considerably hard to get out but still looks very intact and doesnt seem to have any obvious damage. Didnt know if that would be a easy way to make a coil fail.

Tips and Help please. Thanks

 

0300 is not cylinder specific, I'm wondering if you forgot to tighten down some of the hose clamps on the throttle body, or maybe not torque'd down the UIM enough? It's probably a vacuum leak causing the misfire. Check for something that did not get re-connected at re-assembly, and check tightness on the connectors.

I did not look up 1614.