Hi Everyone,

A few weeks ago, I took apart my intake manifold to clean the EGR port. Once, finished and all back together with new gaskets, the car won't idle right. It surges while in park from about 1200-1900 rpms after it warms up. Drives fine. Checked for vaccuum leaks...nothing obvious. It was throwing a code for the TPS, so I replaced that. Didn't help.

Took it to a small import shop, and the tech said he wanted to replace the throttle body and said the PCM was fine. So, I went ahead and purchased a used TB and threw it on myself. Still no change in idle. I then took it back apart and cleaned the IACV. Still not change. If I unplug the IACV while the car is idling, it will still do a short idle bouncing around 1200 rpms, even after cleaning.

I have a friend that thinks the PCM is bad. It was throwing codes a couple days ago for EGR insufficient flow, EVAP, and I can't remember what else as of recently. I can pull all the codes it giving again if that would help.

Anybody have any thoughts on this? I'm about to take it to stealership and be done with it. Soooo frustrated.

Thanks in advance.

 

Don't go to a stealership unless you know a tech there that can vouch for their work.


List the codes you are getting. Most likely you goofed something up when you took apart your mani and cleaned the EGR port.

 

I was having a lot of problems with rough running and misfires. Turned out that our 01 with 134k miles had bad coils. Replaced all 6 coils and it now purrs like a kitten. TCS light and engine light were on before and no longer.

 

I agree with the idea of knowing someone before taking it in. That's a great point. I'm just not sure what else to do. I had help with the EGR port cleaning, so 2 sets of eyes were on it during disassembly and reassembly.

Never have touched the coils...hmm...but I'm open to any and all suggestions.

I'll pull the codes tomorrow morning and list them here. Thanks for your input!

 

Here they are...

P1519 - IACV circuit failure
P0122 - Trottle/Pedal Position Sensor A Circuit Too Low
P1491 - EGR Valve Lift Insufficient Detected
P1399 - Random/Multiple Cylinder Misfire Detected

Of these codes, the OBD scanner says P1519 and P0122 are permanent, and P1491 and P1399 are temporary codes.

Additionally, the little icons on the top of the OBD scanner that were flashing are...EVA, CAT, O2S, and EGR.

I should also mention, I had a friend replace my cat converter a couple months ago when it was giving a CEL for it.

Any thoughts?

 

More info...

I replaced the TB gasket when I originally took it apart (bought it from Napa I think). Not Honda. Bad gasket??

 

Anyone?

 

Well, if no one has any input on my codes/idle issue, can someone tell me how to check my pcm to know if it's bad/going bad?

I know I can buy a used one, but that seems worthless to buy then reprogram if it's not going to fix my problem. And, no, I don't know of anyone with the same car to "borrow" theirs.

 

I've read through my Honda Accord shop manuals over and over. I don't have the tools to troubleshoot properly. But, everything is pointing to the PCM under the assumption the TPS and IACV are functioning correctly...which I am assuming they are since the problem hasn't resolved with 2 different throttle body assys on my car.

I find it very odd that I didn't have these problems until I took apart the manifold for EGR port cleaning.

Still looking for input from anyone...

 

check reference voltage. check voltage at idle. refrence voltage is checked with the car off key on. don't replace the ecu just yet. get cheap tools at harbor freight tools. a ecu could cost you $80+ tools will maybe cost you $20-30 tops

 

Check your fuses, sounds like you may have pinched a wire during reinstalling your intake manifold and may have a short to ground. Replacing the fuses won't fix it you'll have to find the wiring problem. A connector might be altogether unplugged, I doubt that a part failed after taking off the intake. It's also possible that a ground is loose.

 

**********It is now fixed!!***********

Since I travel so much for work and have a company car, I walked away from my Accord problems for a couple months. I came back to it this past week and replaced the EGR valve. That eliminated the EGR Insuffficient lift code. But, it did nothing for the idle issue.

I decided to take it to the Honda dealership. I asked to talk in length with the technician before they even touched it which I did. I explained what I did before the idle issue began and suggested them trying to find a possible vacuum leak or loose connection somewhere. It took about an hour and removing the upper manifold again for the tech to realize that the PCV valve hose was not completely connected causing a vacuum leak. It cost me an hour labor, but the bonus is that they replaced a seat belt sensor for me too for free which eliminated my SRS dash light. Apparently SRS issues carry a lifetime warranty due to safetly concerns. The car runs awesome now and not a single dash light staring me in the face when I drive. Hard to believe that 4 different people didn't notice the disconnected hose before taking it to Honda. Glad it's fixed.