O2 Sensor
 

Can someone please tell me how I figure out which sensor I need to replace. Bank 2 is the supposed culprit. Trying to figure out which one on Bank 2 to replace. Thank you for any help.

What is the reason for you wanting to replace the O2 sensor? Do you have the DTC (diagnostic trouble code)? You might consider testing the sensor first before replacing it and it not solving whatever problem you're having.

P0174 popped up. I cleared it and it came back a few days later. This time I left it to see if it would clear on it's own and it didn't. What else could it be? Only other thing I can think of is I changed my air filter and the old one was nasty. The first time the code popped up was the day after changing it. Both times it popped up was Bank 2.

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A dirty air filter wouldn't cause that code. Before slinging parts at it, try searching for a vacuum leak as that would also cause this code. If there isn't one, I suggest testing the O2 sensors before replacing them. If the O2 sensors are good, I would perform a valve adjustment as this has cleared the P0171 code for some folks on this site (myself included) even though some people think it's impossible and that it was a freak instance/bad tank of gas.

A dirty filter may not but what about changing to a new one from a filthy one? P0171 is Bank 1...No? Different possibilities right? I will check for vacuum leak and test the sensor. I guess valve adjustment could be possible considering my timing belt went and I got pretty lucky and have no major problems. Car drove fine for first two weeks after replacing timing belt before I replaced the filter and the P0174 popped up. I assumed if the valves were an issue the code would have popped up in those first two weeks. Anyhow, thanks for the advice.

The ECU in our car is very smart... it can adjust to things relatively quickly and adapt well to various conditions. I think it's extremely unlikely that changing the air filter is causing this.

Damn dude, what do you mean by "your timing belt went"? How many miles on the clock?

The way I see the possibilities: either a lean condition exists or it doesn't.

If it does, it only exists on one bank, so the problem is one that doesn't affect both sides. So it's probably not your MAPS. I think the most common cause of lean codes is a vacuum leak. But it's certainly not the only cause. It might also be a problem with the fuel system on just one rail (not enough fuel), but this is more difficult to troubleshoot.

If a lean condition doesn't exist, then your sensor is lying to you (also fairly common) and you'll need to troubleshoot it to find out.

Long story short, timing belt broke while driving about 45. Didn't completely snap and stayed on all pulleys. Had it done 25,000 prior. So replaced everything again and I guess I got lucky because it is purring like a cat. Runs great. Back to the P0174, friend of mine is an Acura Tech and he just called and said I need a software update. I will try that first and go from there. 2007 Base currently at 135,000.