p0505 and p1505
 

I am getting these two codes on my 2003 EX, after doing a headgasket and timing belt install. I have checked for vacuum leaks and cant seem to find any. I read here that by starting the engine with the air filter off and putting your fingers over the IACV hole in the throttle body helps you determine vacuum leaks. I did this and the engine stalled out. Any idea what could cause this?

Right now the car starts and drives fine. Once it gets to operating temperature it starts to fluctuate in idle

thanks for any help.

EDIT: I took a video after cleaning and the throttle body and all sensors.
http://www.youtube.com/watch?v=8Qdd7sP9uSo

Re: p0505 and p1505
 

Here is an update for this. I still have not found the problem. I took everything down to the valve cover off and checked for anything unusual and found nothing. I also put the old pcv valve in just in case I got a defective one. I have tried all the idle learn procedures I can find.

It starts and idles high, around 1000-1500 Rpms. After warming up it begins to bounce between 1000-2500 continuously. Today I unplugged the MAP sensor while it was bouncing and that actually steadied it out but still didn't bring it back to normal. I am stumped!

Re: p0505 and p1505
 

usually bouncing rpms is due to a bad TPS sensor on the throttle body, which also affects how the car drives when warm esp with an auto trans. could be you damaged the sensor or it just went bad. but the codes say iac and pcv so i would look for a vacuum leak somewhere. check all the hoses. did you try cleaning the IAC valve? could just be clogged.

Re: p0505 and p1505
 

Check:
1. Timing
2. plugs
3. air cleaner
4. PCV system (pinch the PCV hose and you should hear the valve clicking if it's good)

I had a leak in the valve cover gasket that took forever to find. When you check the hoses again check the gaskets too. You can spray carb cleaner (carefully) to pinpoint the vacuum leak.

I would also clean and inspect the throttlebody and IACV. If you figure out that you need a new TPS then find a whole throttlebody on eBay or CL, drill the rivets, and replace them with bolts.

Re: p0505 and p1505
 

Ok I just removed the throttle body and gave it a thorough cleaning. I cleaned out the iacv and map sensor as well. I'm still having this problem. I have been reading about a idle adjustment screw and a fitv valve. Does my 2003 ex have either of those?

Re: p0505 and p1505
 

Updated with a video, I just bought a new used throttle body off ebay with all the sensors, when that gets here I will install it and report back.

I checked the hoses and do not have a vacuum leak, and tried 2 different pcv valves and it still throws the code.

Re: p0505 and p1505
 

I just finished the same job tonight (head gasket & timing belt) when replacing the head on my '03 EX and my car has the same exact symptoms. I am getting DTC codes P0515 and P0505, and the idle is oscillating between about 1250 to 2250. I am going to have to do some troubleshooting tomorrow and I'm interested if you figured out what was causing it on your car. Did you find the cause yet?

Re: p0505 and p1505
 

Turned out to be air trapped in the cooling system. Bled the system with a funnel while "massaging" the upper & lower rad hoses for a long time. Next I reset the ECU and no more hunting idle.

Now that the idle hunt is gone, a different idle issue has appeared, the idle is rough around 800/min and I'm getting codes p0172 and p1129. Going to research this now.

Re: p0505 and p1505
 

Bad MAP sensor (P0172) or connection is probably the cause of the rich fuel mixture (P1129). Unfortunately the ONLY thing the service manual says is to read what the sensor is saying with a diagnostic tool that has data feed (reads and/or actuate sensors) and replace the sensor. So the only things to do without a diagnostic tool is to look for a bad wire/connector then replace the sensor if no bad connection.

Re: p0505 and p1505
 

I'm hoping it turns out to be the MAP sensor itself, and not that my brand spanking new timing belt has slipped a tooth.

Re: p0505 and p1505
 

Well, the price could be worse: https://www.hondapartscheap.com/inde...AKE%20MANIFOLD

Re: p0505 and p1505
 

Hi
i am having the same issues here!!!! P1505 code? found a solution yet!!!!!!

Re: p0505 and p1505
 

Hey all - I know this thread is OLD but I thought this might help someone out...
I had an intermittent p0505 and p1505 CEL on 2002 honda civic ex
First, I tried a new IACV from junk yard, seemed to fix problem for a while, then came back
Then, I thought junk yard IACV went bad, replaced w/ eBay part
but p0505, p1505 persisted

Then, I thought it was a leaky vacuum hose or something - so I replaced literally every vacuum line in the car, and covered nearby possibly leaky component in carb cleaner to try to find a leak...no fix..no leak..

Then, I replaced the PCV valve - cuz it was $10 and I figured what the hell.
No improvement, p0505, p1505 persist:hithead:

Then, I went to junk yard again, got a full throttle body, with IACV, TPS, and Purge solenoid all on it, and swapped it out (I cleaned up TB first)
So far, 3,000 miles after switching TB, no CEL!!

Honestly - if I could go back in time, I would have just replaced the valve purge solenoid (36162-PLC-003) on the TB. But, I suppose it may have been the TPS too.

Hope this helps someone out...

p.s. after each time I played with something I made sure to purge as much air as as possible from the coolant system

Re: p0505 and p1505
 

Hey maybe this helpa i recentlybhave done the y8 covertion on my 2002 ex and befour had no check engine light. Bit after had those codes and i didnt plug the 2 sets of spouts on top and bottom of throtal body. 100% thats waht it is on my car 100% maybe helps you out

Re: p1505
 

Hey i know this thread is old but to the civic family.did anyone every figured out whats the cause for the p1505 code. im having the same issue with 7th gen 02 civic, vtec and i would need some solution. I took it to a shop and they cant fine any vacuum leakes.