2003 Audi A4 Quattro, 1.8t Misfires

Question

Showing codes for multiple misfires, and running to lean. Thought it was fuel issue at first, brought it to a audi mechanic who said it was my sparkplugs.. while I had changed them upon the misfire. Had it brought to 2 others and they said the same thing.

In short, it wasn't the sparkplugs lmfao. Got told my pressure in my exhaust system was 6psi, and was told to do my Catalytic Conveter, which was done tonight with a ton of effort. As I was snooping around my engine, I noticed my Crankcase Breather Tube was broken off going into my engine under the Manifold. Could that possibly be causing the misfires? I'm aware that the audis in my year had issues with the PCV, but didn't think it would just break off🧍‍♀️ Car also dies at low idle/light at random intervals, using my other car at the moment

2003 Audi A4 Quattro Automatic 1.8T engine turbocharged

Answer 1

If the broken piece is going directly to the intake manifold, then it absolutely can be the cause your misfires. When there's a manifold leak of whatever size or means after the throttle body, this allows unmetered air to enter the intake tract, which can cause a lean condition. When the air/fuel charge is too lean, it will cause misfires and all other sorts of running issues. I'm pretty sure if/when you get this replaced, it will most likely solve your problem. At the very least, it needed to be fixed anyway.

Answer 2

Totally dependent on how many cylinders are misfiring. Do you have misfire codes specific to a single cylinder or just a generic misfire code? If all are missing and you are running lean it’s either lack of fuel or too much air. Probably too much air if the crankcase brother tube was fully broken off. This will be reflected as very lean, generally above +15% fuel trim correction