That looks like the knock sensor, I'm not sure though

 

Arghhhh the saga continues! Prelude is on a tow truck on its way back to the Honda dealer now. When I changed the wiring harness, everything worked fine I thought. It threw the same codes as always (9), so I didn't think anything of it. I had to wait on the thermostat housing crossover pipe gasket to finish up though because the coolant was leaking and I couldn't drive it around to really test out the wiring harness. After I got that going today, I got all of about 20 feet into the middle of the street when the car died. Started right up, then stalled again. Did this about 5 more times as I coasted down a hill to my eventual stop.

I was just going to have the guy I'm working with at the dealer diagnose the CYP sensor issue first, but now there seems to be even more fun around the corner...

With the P73 ECU, I am getting CELs that are 2 longer ones followed by 1 short quick one.
But with the P72 ECU, I get codes 3, 5, and 9. So I don't know how I went from only a 9 on the P73 and only a solid CEL on the P72 to now having all these crazy codes. And I'm not getting much exposure or help here so I'm going to try to get my questions out in another arena around here to possibly get some help on this. I really need it guys because tomorrow the tech is going to want to know what to do with this car. And I don't even know which ECU to try to continue diagnosing these problems on...

 

Bump for help...

 

Anyways, looks like I'll be buying a new crankshaft position sensor. Or cylinder position sensor. OR whatever you want to call it. Different names for different cars sometimes. One Honda dealer wants $324. Another one wants $294. They won't have it for 4 days. The local Advance Auto Parts store has one (BWD brand) for $100 less and it will be here tomorrow. I think I'll go with that. I know they say not to get anything other than what mother Honda gave you from the factory, but something tells me I'll be OK. We'll see if that fixes my CEL...

 

In the original post, you mentioned this:
I can't even accelerate past some grandma in her Subaru Outback to change lanes and get on a highway.
Now, check inside the distributor and look for the yellow/blue negative coil wire. See if that wire is loose. Once, when dirving, I accelerted and then, BOOM, dead. I thought the worst. Fortunately I had a bag of screwdrivers, and decided for some reason to take the cap off. The negative coil wire blew off! Months later after starting the car it ran sort of funny but not to noticably different. But acceleration was crap. I thought it was running on 3 cylinders, but it wasn't choppy. Maybe lack of air, but no resrictions. I decided to look in distibutor again and that same wire was loose and freyed. Then the quick connect broke off. The problems are likey disributor related as mentioned in the secondary thread. In my sitation the cyp is also always throwing a code, time for new distributor. May be the same for you.

 

Wow, someone in the same boat as me kinda haha. Do you have a chipped P72 ECU? Or are you just running the stock Prelude ECU? I guess that doesn't matter if it all comes down to the CYP sensor.

Let me know if that fixes your problem. I will certainly let you know if it fixes mine. I ordered a new distributor today and it should be here in 3-4 days. Replacing it doesn't seem too difficult.


PS: mtber was right. I did have the TPS and MAP sensors backwards. Don't ask me how. I guess I switched them around when I did my thermostat and housing gasket fix because I was in a hurry to get it running. So as soon as I swapped those two wires I was able to drive home from the dealership. Funny that the mechanic there didn't seem to notice that lol.

I guess I will be able to return my CKP sensor that I bought since I don't think I need a new one after all. It's gotta be the CYP sensor. That's the only code it throws with the P73 ECU now. Still runs crappy (slow and horrible mpg), but the CEL comes and goes, it's weird....

...But on the P72, it runs worse. I guess that's because of the CYP sensor? Btw, it does now throw the CYP sensor code on the P72 ECU also, along with that VTEC code again. I wonder why it doesn't throw the VTEC code on the P73? Oh well.

I am eager to get this thing fixed. I don't know if after a new distributor/CYP sensor if it will run right finally. Wouldn't it also throw codes for being too rich? Which would point us/me in the direction of new H22 injectors like Phearable recommended from the get-go.

 

New distributor fixed my CYP check engine light code 9! Hip hip hooray!

Now, CEL code 3 for the MAP sensor popped up.... ugh

 

I guess I know more today than I did at this time yesterday, which is always a plus. I'm still confused and frustrated though.... just as CEL code 9 disappeared (which is AWESOME) with the new distributor, the CEL code 3 for the MAP sensor came back. And at first, it was only code 3. I have spent all day trying to diagnose this issue. At the end of the day, it started throwing another CEL code. I think it's 21 or 22 like previously mentioned? Here is a video I took:




But anyways like I said I spent all day trying to track this crap down. Here is a break down of the voltages I measured on the MAP sensor at the sensor itself... these are with the key on, engine off.


With the engine running, the power and ground voltages stay the same while the sensor wire voltages range from 0.85v - 0.89v.

I checked the voltages on the same wires at the ECU harness and they all read the exact same as well. So there is no break in continuity or a bad ground I don't think? My MAP sensor reads:


So I went and bought a brand new MAP sensor at the auto parts store, just to double check that it wasn't my MAP sensor that was bad, ya know? Sure enough, the brand new MAP sensor checked out at the same exact voltages as my current one. So that was good to know that I didn't need to spend $70 on one of those...

I pulled the MAP sensor off while the car was running and there is definitely vacuum on/at the hole. The gasket is intact (o-ring). The connector seems plugged in tightly. I really don't know what's going on anymore. I do know that I went through 1/2 tank of gas today though. And I drove probably a total of 40 miles maybe? Emphasis on MAYBE?

I heard having a bad/clogged catalytic converter can/could cause a MAP sensor issue... and I definitely have a bad cat I know that. But I don't want to replace the cat and have it go bad a week later because I'm running so damn rich that it ruins the new cat. That doesn't help me at all.

It's interesting now that the P73 JDM ITR ECU is throwing the same VTEC (?) code(s) as the USDM chipped P72 from Phearable. My next guess/step is to go throw the P72 ECU on there and see how it drives now that the distributor issue is fixed....

Suggestions/comments welcome and appreciated!

 

I now throw these codes after replacing the VTEC solenoid switch gasket stuff:

http://www.youtube.com/watch?v=nomlj...layer_embedded

MAP sensor again. Woo hoo. Still makes no sense whatsoever. Checked voltages and continuity. The sensor isn't bad. The wiring isn't bad. It all points to the ECU at this point. But everyone keeps telling me to diagnose these problems on the P73 ECU, which doesn't make much sense to me because I don't ultimately want to run the P73 ECU, obviously. The idea here was to get it to run correctly on the chipped Phearable P72 ECU. While I have been told the reason it does not is because of my CELs, I still don't understand why I wouldn't want to use the P72 to DIAGNOSE these problems versus using the P73.

Anyways, I have a bad feeling I am going to have to end up spending $500 on a Hondata S300 system, just so someone local will take me seriously. A Honda tuning shop yesterday called Import Sports Performance totally blew me off and told me I needed an S300 system before they would even touch my car. So that's $500 for the S300, $50-100 to install it (depending on who I go through), and then that's all assuming I can use my current $355 package deal from Phearable (P72 ECU, conversion harness, and chip)...which I know I can't use the chip and stuff but if I have to go Hondata man what a ****ing waste of money. UGH. Then they want $295 to tune the car. THEN on top of all that, $65 to diagnose each Check Engine Light code.

I am going to ****ing tear my hair out here!!!!!!

 

Pull your cat off and gut it out. Put it back on see if that helps. Of course you won't pass emissions until you get another converter. I had a converter come apart on me stop up my muffler and i could go WOT and it would only turn 3500 - 4000 rpms.

 

Yeah, a clogged cat will cause all sorts of issues, so if you don't need your emissions test right away, just gut the one on the car, and find a new/ used oem one for e-tests.

 

Well the idea is that when I get my OBD1 ECU working, I won't need to worry about that rear O2 sensor so yea, I was thinking about a test-pipe. They're cheaper anyways.

Or yea, I'm considering a $300 installed by a local shop new cat.