I cleaned the IACV. I haven't done the PCV. I looked in the service manual and saw that it's accessible from the top of the engine compartment right? Is this something I can clean or will I need to buy a new one? If the PCV valve is dirty or messed up, could that affect fuel econ?

 

Accessibility varies by engine. The valve is accessed from the top of my D16Y7 and from the bottom of my D16Y8.

The valve is cheap ($2-$3) so just replace it. Also make sure the PCV and breather hoses are clear so that air flows freely through them.

Definitely.

 

I will definitely try that. I have the D16Y7. It's kinda deep in there right? The grey and blue plastic thing?

 

Yeah, follow the black rubber hose from the intake manifold (below the IACV) to the breather chamber below the fuel rail. Not much room to work there. I had to remove the air cleaner and the throttle cable bracket to increase the work space.

 

Ok, I'm sorry to bring this thread back up. I finally got into a Honda dealership yesterday to get a replacement PCV valve. What the handed me was a tiny black plastic elbow breather valve. While I'm confident this is likely the correct part (as it looks similar to the drawing in the diagram in the post before me) I thought it was supposed to be blue/black plastic. When I look in my engine compartment, I do see a blue/black plastic apparatus that looks a bit different than what was handed to me. I didn't end up buying it.

This is what it looked like:



It was all black though... no blue. Is this what I want though? Sorry, just making sure. $23 is a lot of money for me (especially for such a small dumb piece of plastic). Thanks again....

 

The valves look fine. I buy mine from AutoZone for less than $3.

 

Alrighty, I'm fairly douchetastic for bringing this ridiculous thread back but I finally had a chance to replace the PCV valve during spring break and have driven two tanks worth of gas. While the car's acceleration is definitely snappier with the new valve, I'm still getting about 27mpg and my idle often dips down to about 500rpms (according to the tachometer anyways) making the car sort of shudder a little bit.

Anyone have any pointers for the next step I should take? There's still some things I haven't done that I plan on doing (or having done professionally, at least for timing belt) and I'm not sure what order I should do these services:

Replace fuel filter
Change tranny fluid
Flush fuel injectors
Change timing belt (it was done at 60k miles and I currently have 120k miles)

Honestly, I don't know if any of the above items could help my sporadic, shuddering idle, or semi-low fuel economy... I'm open to any advice...

Thanks a ton for any advice... I'm not really dying with the low fuel economy, I just want to make sure I'm hurting anything by possibly running too rich...

 

Have any CEL codes reappeared?

Is 27mpg from highway, city, or mixed driving?

Is the header cracked or any notable leaks in exhaust system near the primary O2 sensor?

Is there a leak from the vacuum hose attached to the fuel pressure regulator?

Does you smell gasoline in the exhaust? One of your fuel injectors may be stuck open?

The primary O2 sensor may be faulty but not throwing a code.

 

No CEL codes. I just checked the other day in fact. The exhaust at times smells a little gassy. I've actually been curious about the exhaust as it is louder than I would imagine, but when looking at the exhaust line, I don't see any notable holes. Maybe I should get under there and look really hard? I don't know how to check for any of the leaking that you mentioned... The 27 MPG is freeway, sorry, I should have mentioned... how would I tell if a header is cracked? Just visibly inspect the whole thing I suppose?

 

For the exhaust system, put the front end on stands and take some time visually inspecting it for cracks, holes, bad gaskets, or loose connections.

For the fuel injectors, turn the key to ON(II) for a couple of minutes without starting the engine, then pull plugs out and check for gasoline in the cylinders. There should be none.

Inspect the fuel pressure regulator (FPR) vacuum hose and connections for leaks. If the hose is cheap, just replace it. You'll need to measure the fuel pressure to test whether the FPR itself is bad.

You need a good scan tool to check whether the O2 sensor is faulty.