[1funryd]

OBD0 is easier to work on than newer OBD diagnostics. Its simpler.
So that shop is dumb.

And how did he determine it was OBD0?
If it came with a B20a5 then yes, it is OBD0, but a B21a1 is OBD1 and thus would be running a Pk3 ecu.
What ECU do you have?
Did you check?

And why are you not reading up on how to post pics, pics are now a requirement if you want help in this day and age.

Posting a pic is easy, just click on the picture icon at the bottom of the post window, and then browse to your computer or whatever storage you have it in and upload it.
You can upload only 10 pics at a time, so if you need more, then I suggest you take up additional posts in your thread to give you the space you need to upload them.

 

[luzer]

I found the pics. It looks like a nice car!

You even have headers! But those look like b21a1 headers with only 1 sensor. And if it only has one sensor than it is obd1 most likely. Unless somebody did some goofy stuff.

You can load pics through the gallery or through the button to the left of the camera button when typing.

So I was under the impression that it should be OBD1 too, but i took it to a shop yesterday who refused to work on it because it's obd0

@m4tty your shop is correct. Your car is a 2.0Si and originally came with a b20a5 and is OBD0. It's obvious in looking at the intake manifold and the number of vacuum lines going into the end of the plenum near the brake and clutch master cylinders (pics below). There is a pretty simple o2 sensor conversion that a previous owner may have done on this car. It would be much easier than converting it to OBD1. There are other indicators it is a 2.0Si as well, such as the manual side view mirrors. You don't include an interior pic but I the seats can tell you too.

B21A1

OP's engine bay (B20A5)

 

[m4tty]

@m4tty your shop is correct. Your car is a 2.0Si and originally came with a b20a5 and is OBD0. It's obvious in looking at the intake manifold and the number of vacuum lines going into the end of the plenum near the brake and clutch master cylinders (pics below). There is a pretty simple o2 sensor conversion that a previous owner may have done on this car. It would be much easier than converting it to OBD1. There are other indicators it is a 2.0Si as well, such as the manual side view mirrors. You don't include an interior pic but I the seats can tell you too.

B21A1
View attachment 39931

OP's engine bay (B20A5)
View attachment 39933

Thank you for the clarification! May I ask why you suggest an O2 conversion kit over and OBD1 conversion? Again, idk much, but wouldn't OBD1 be better in the long run from a diagnostic standpoint?

as far as @Sam91 's question, as of this moment my plans are coilovers and alignment today, then before anything else I need to figure out what's going on with the charging of my battery, the dash light flickers and it's been dead the past two mornings. (pretty confident my alternator is shot but a lot of wiring looks like sh!t too.) and figure out why I have a surging idle. After that is when I'll continue to think about what I really want for my prelude

(Will upload pics of coils when its done)

 

[m4tty]

OBD0 is easier to work on than newer OBD diagnostics. Its simpler.
So that shop is dumb.

And how did he determine it was OBD0?
If it came with a B20a5 then yes, it is OBD0, but a B21a1 is OBD1 and thus would be running a Pk3 ecu.
What ECU do you have?
Did you check?

And why are you not reading up on how to post pics, pics are now a requirement if you want help in this day and age.
View attachment 39930


Posting a pic is easy, just click on the picture icon at the bottom of the post window, and then browse to your computer or whatever storage you have it in and upload it.
You can upload only 10 pics at a time, so if you need more, then I suggest you take up additional posts in your thread to give you the space you need to upload them.

It originally had a B20A5 and whoever had it before me swapped it to a B21A1 which is why it's OBD0.

Wouldn't OBD1 make diagnosis easier and give me options of tuning in the future vs OBD0?

 

[luzer]

Thank you for the clarification! May I ask why you suggest an O2 conversion kit over and OBD1 conversion? Again, idk much, but wouldn't OBD1 be better in the long run from a diagnostic standpoint?

as far as @Sam91 's question, as of this moment my plans are coilovers and alignment today, then before anything else I need to figure out what's going on with the charging of my battery, the dash light flickers and it's been dead the past two mornings. (pretty confident my alternator is shot but a lot of wiring looks like sh!t too.) and figure out why I have a surging idle. After that is when I'll continue to think about what I really want for my prelude

(Will upload pics of coils when its done)

I was addressing Sam's comment about your engine not appearing to have two o2 sensors, not suggesting that you do that. I was just saying that a previous owner of your car may have done that o2 conversion. One reason why someone might do that is a header they wanted to install was for a b21a1. Here is a write-up from years ago in case anyone else may want to do that...

http://www.preludepower.com/forums/showthread.php?t=263824

 

[Sam91]

Thank you for the clarification! May I ask why you suggest an O2 conversion kit over and OBD1 conversion? Again, idk much, but wouldn't OBD1 be better in the long run from a diagnostic standpoint?

as far as @Sam91 's question, as of this moment my plans are coilovers and alignment today, then before anything else I need to figure out what's going on with the charging of my battery, the dash light flickers and it's been dead the past two mornings. (pretty confident my alternator is shot but a lot of wiring looks like sh!t too.) and figure out why I have a surging idle. After that is when I'll continue to think about what I really want for my prelude

(Will upload pics of coils when its done)

For your alternator you could take the car to your local autoparts store such as oreillys and they can test the alternator on the car.

Also take a look at your crank pulley. B21a1 crank pulleys are notorious for separating. Mine went out and I think it being off balance screwed up my alternator. So I had to buy one of those as well.

 

[1funryd]

It originally had a B20A5 and whoever had it before me swapped it to a B21A1 which is why it's OBD0.

Wouldn't OBD1 make diagnosis easier and give me options of tuning in the future vs OBD0?

Depends on what tuning you are planning on doing.
If you are going to swap the motor out, then yes OBD1 is the better option.

However; when going OBD1 for tuning for a swap is different than OBD1 conversion just for the bastard B for tuning which is proven not to respond to tuning at all.

You will have to do a massive conversion to OBD1 via custom engine harness and some wiring tapping to setup the new motor swap and then purchase the P28 with Hondata S300 ECU is the best option for tuning for our chassis.
Or you can do Haltech which is another option but is a $1500+ option.

 

[m4tty]

For anyone curious about an update regarding my car, the coils are on and look+work fantastic. HOWEVER, when one thing goes well 2 things have to stop working well, as are the laws of nature. Took the car to get aligned and have the charging system checked out, am told the battery is dead but alternator is fine. So I buy a new battery, and to my surprise the dash light turned off, surging idle stopped, and everything is cool right? So so wrong. I then discovered that my steering rack and pinion are shot and need to be replaced. But not too bad, until an hour into my drive home (about a 2hr drive), my whole dash stops working, all electronics die, and the engine quits on me. Jumped it, waited about 20min, got back on the highway.
15min later? SAME THING, ended up towing it home and am now on the hunt for parts.

TLDR: New coilovers are on, but steering rack is toast, and alternator is shot despite being told it was fine!

Boy oh boy what have I gotten myself into lol

 

[Sam91]

For anyone curious about an update regarding my car, the coils are on and look+work fantastic. HOWEVER, when one thing goes well 2 things have to stop working well, as are the laws of nature. Took the car to get aligned and have the charging system checked out, am told the battery is dead but alternator is fine. So I buy a new battery, and to my surprise the dash light turned off, surging idle stopped, and everything is cool right? So so wrong. I then discovered that my steering rack and pinion are shot and need to be replaced. But not too bad, until an hour into my drive home (about a 2hr drive), my whole dash stops working, all electronics die, and the engine quits on me. Jumped it, waited about 20min, got back on the highway.
15min later? SAME THING, ended up towing it home and am now on the hunt for parts.

TLDR: New coilovers are on, but steering rack is toast, and alternator is shot despite being told it was fine!

Boy oh boy what have I gotten myself into lol View attachment 39944 View attachment 39945 View attachment 39946 View attachment 39947

Dang! That sucks! It seems like 3rd gen preludes have alternator problems. The previous owners shop replaced the alternator on my car like 6 times before it started working right. That was like in a year time frame.

I had my alternator go out last year along with my crank pulley. I got a reman from oreillys and it has been working fine since.

Also don't throw those old shocks away. They look to be lowering springs on performance shocks. They should be worth something.

What brand of coilovers did you go with?

 

[1funryd]

Those coilvers look like D2's.

 

[m4tty]

Dang! That sucks! It seems like 3rd gen preludes have alternator problems. The previous owners shop replaced the alternator on my car like 6 times before it started working right. That was like in a year time frame.

I had my alternator go out last year along with my crank pulley. I got a reman from oreillys and it has been working fine since.

Also don't throw those old shocks away. They look to be lowering springs on performance shocks. They should be worth something.

What brand of coilovers did you go with?

I gave the coilovers to a friend of mine, because he's much more active on Facebook marketplace than I am. One of those shocks is completely done though, absolutely zero pressure in the spring.

I went with the D2 Racing coils, a little pricey but even in the short amount of time I drove it before the alternator quit, it feels SOOOO nice. And I'm very happy with it.

As far as the alternator goes, would you recommend buying from someone like O'rielly's or
Advanced instead of eBay? Just thinking that because if the same thing that happened to you happens to me it'd be better to use their warranty right?

 

[Sam91]

I gave the coilovers to a friend of mine, because he's much more active on Facebook marketplace than I am. One of those shocks is completely done though, absolutely zero pressure in the spring.

I went with the D2 Racing coils, a little pricey but even in the short amount of time I drove it before the alternator quit, it feels SOOOO nice. And I'm very happy with it.

As far as the alternator goes, would you recommend buying from someone like O'rielly's or
Advanced instead of eBay? Just thinking that because if the same thing that happened to you happens to me it'd be better to use their warranty right? View attachment 39949

Nice! Hopefully I will install ksports this summer. But I am hoping to do an engine rebuild prior to that.

I would buy an alternator from a parts store. That way you have a life time warranty and if you ever have issues you can get it next day without issues. Ebay is fine but the warranty thing night get iffy.

 

[m4tty]

Nice! Hopefully I will install ksports this summer. But I am hoping to do an engine rebuild prior to that.

I would buy an alternator from a parts store. That way you have a life time warranty and if you ever have issues you can get it next day without issues. Ebay is fine but the warranty thing night get iffy.

Yeah that's kinda what I assumed, O'Reilly's is the best lol

I looked into the Ksports but because of all the other issues I need to figure out I stayed in the "middle-ground" with the D2's

 

[Sam91]

Yeah that's kinda what I assumed, O'Reilly's is the best lol

I looked into the Ksports but because of all the other issues I need to figure out I stayed in the "middle-ground" with the D2's

Oreillys is the best. I work at one. Lol.
It's funny a bunch of my coworkers even my manager used to work at autozone. Lol

You'll have to keep us updated on how these d2s are!

 

[luzer]

I haven't been to an Autozone since they were called Auto Shack LOL. I usually go to NAPA since that's the only auto parts store in my town. Oreilly's is almost 30 minutes away in another town.

 

[m4tty]

@Sam91 As someone who’s never replaced an alternator before in their life, any tips or tricks that’s i should keep in mind? I’d really like to do it myself but i’d hate myself if i caused more damage lol

 

[1funryd]

Yeah that's kinda what I assumed, O'Reilly's is the best lol

I looked into the Ksports but because of all the other issues I need to figure out I stayed in the "middle-ground" with the D2's

FYI D2's are Ksports rebranded.
I brought Ksports to the community in 2007 and for a few years I was hearing rumors that D2's were equal to them, and in looks alone they are.

But then I got Ksport to admit to me that they were the same just rebranded technically for a different market but since we are now a global economy now, that just all bled into each others space.

There were even a thread in Honda-tech.com that showed both side by side taken apart and compared the shims as well.

 

[Sam91]

@Sam91 As someone who’s never replaced an alternator before in their life, any tips or tricks that’s i should keep in mind? I’d really like to do it myself but i’d hate myself if i caused more damage lol

Here is a video I made when I did mine. It's pretty easy compared to some cars.

 

[m4tty]

@Sam91 As someone who’s never replaced an alternator before in their life, any tips or tricks that’s i should keep in mind? I’d really like to do it myself but i’d hate myself if i caused more damage lol

Here is a video I made when I did mine. It's pretty easy compared to some cars.

you’re awesome man thank you so much

 

[Sam91]

you’re awesome man thank you so much

Your welcome. That is why I like making videos. It has been like 4 months since I made a new one though. I would rather be getting stuff done than filming. But I have a lot of plans this summer I am hoping to record.