So, I've owned an 06 accord(j30) v6 6mt and now own an 06 TL(j32) 6mt for the past year and some change or 74k miles. I've always owned acuras and hondas and am having an issue with my TL. I know a fair amount about the mechanics and systems in place in these engines but am having a tough time with this issue. My TL... I bought this vehicle at 200k and it has run like a top up to 270k. Recently I've had a lack of throttle response/performance. The vehicle has thrown a cel for catalyst efficiency below threshold and a code for the bank 1 upstream sensor, however, the vehicle has not thrown a cel consistently and the cel comes on, then goes off on it's own. Currently it will not throw a cell, and I drive it from 9am to 5pm every day. But the performance is subpar most definately. It takes alot of gas pedal to get it moving and even then it does not move as the TL normally moves. I've checked the exhaust system for restrictions but nothing seems to be clogged or restricting. Have changed the firewall side cat, disconnected the 3rd cat and drove it with no changes, so it's not the cat, resonator, mufflers, etc. Replaced the PCV valve, no effect. Oh, and I just took it to the most reliable mechanic I know and they said it is running lean at idle, bit to bring it back once a CEL is thrown for further diagnostic. I'm at a loss. Some other info is the front(radiator) side valve cover gasket has been pushing oil out since the issue started. I thought there was excessive backpressure from the exhaust(maybe a cat) being restricted but that doesn't seem to he the case since I've replaced the read and removed the 3rd with no difference in performance. Thanks in advance for the knowledgeable input!

I've replace the bank 1 upstream 02 sensor as well as that(firewall) cat and no change.

Symptoms are the throttle response is sloppy as in, the vehicle runs "OK" up to 2700-3000rpm, but then studders and falls on its face above that.

MODERATOR NOTE: Thread moved to model specific forum.

Battery Cables
 

I understand that you have already checked your battery, but did you also check your battery cables (wires)?

The TL's are pretty High Tech so my guess is that they really depend on the correct voltage and amps, which obviously equals having the correct ohm's. My buddy owns a 2006 TL with about 130,000 miles on it. It was having a number of odd issues, but his main issue was delayed shifts, especially into 3rd or 4th gear (I don't recall specifically). So I helped troubleshoot and noticed that he had a small battery. Looked up what battery he should of had and found he needed a much bigger one (had a 600 CCA - 750 AMP). So we bought a 800 CCA - 950 AMP Battery. That's when we realized he had the most corroded battery wires I've ever seen in my life! Both wires going to the POS terminal were green and disintegrating all the way through and down the length of the wires! It wasn't too obvious at first. We were going to simply cut away the first couple of inches and be done with it. But to our surprise it only got worse! He may as well been using speaker wire!

We changed out the battery and all battery wires. Not only did this fix the transmission slipping issue, but his car ran like it was brand new! Note that it didn't seem to be running that bad to begin with, except for the transmission and a couple of other minor issues with dashboard lights going on and off randomly, but WOW! It seemed like he gained a lot more HP - Crisper shifts (Automatic Trans), and no more odd dash lights!

Try resetting the ECU?

Without knowing what the fuel trims are doing and how the O2 sensors are reacting at various RPMS this could be a difficult DIAG. Lean condition at idle could be something as simple as a vacuum leak.

it's 6am, just woke up from a dream that my car wasnt accelerating properly in traffic...it's sputtering and i look behind and there's a million cars honking at me

Did you check the air filter?