brushie_

Hey, my A4 has been running rich for a while now, but not enough to trigger a CEL or anything. It will actually drive just fine as well, but you can smell the fuel and the long term trim on both banks is about -18. It was actually way worse before I replaced the MAF sensor, always tripping a CEL and sputtering a lot, but now it's stinky but drivable.

I've replaced the spark plugs (old ones didn't look like they were from a rich running engine, still have them if someone wants pictures), Evap Purge Solenoid, MAF, vacuum lines, PCV tubing and valve itself, "tried" to clean the throttle body, and a new air filter. Also reading my o2 sensors, I can't tell if they're being slow, or if my OBD2 reader is just slow. I also know one of the cats had been recently replaced as well.

clancy

brushie_

Okay so I'm gonna go ahead and do a fuel pressure test, pretty sure the leak down test will finally point out the culprit (my bets are on the fuel pump). Looking around I noticed that tapping into the fuel line had a VAG tool (1318) and I wanted to make sure if this is something that isn't unique to this, and that any fuel pressure tester can do the job. Just don't wanna rent one out to find it doesn't fit.

clancy

brushie_

I actually took the rail out with the injectors still attached, put it to the On position to check if any of them leak. They were kinda dirty above the o-ring but no leaks. The only odd thing I saw was that one of the injectors (Cylinder 1) was red instead of blue like the others. It was still an Audi/VW injector with the branding and everything but that's about it.
I'm also looking into checking the plug wires and coil pack since the pump was replaced not too long ago. The only other symptom I know of it that after being warm, it'll have a bit of an issue starting, like it's about to stall but then fixes itself back up. I heard a bad coolant sensor can cause this, replaced it, and now it does it less frequently.

clancy

brushie_

I could look into cleaning them, but I also did run a tank with the Redline fuel cleaner inside as well.

brushie_

Quick question about these engines, Bank 2 usually is the one that has a higher Long Term trim (19-21) and Bank 1 is usually always lower or equal to Bank 2. If one injector was dirty, bad, etc. on one bank, would that still cause the other side to have a rich condition? I always thought that a injector problem on one bank will only have the Trims affect that one bank, and the other would be normal.

Also, are the injectors okay to testing using 12 volts or should I use a 9 volt battery when testing the spray pattern?