1989 civic dx sedan d15z1
 

Hi
I'm new on here. I just recently swapped a d15z1 motor into my sedan with the original dx transmission. I'm hoping ill get atleast upper 30s than later on swap to an hf. currently Im using a dx transmissions. I've converted my car into obd1. Ive Lowered it with ground control & tokico blues. I've installed headers but honestly I think headers are not the best with d15z1 motor, because of the 02 sensor. I've been experiencing a lot of hesitation and my 02 sensor light came on when the sensor is only two weeks old??.

Welcome to the forum!

Back in the day, the founder of gassavers.org was going to do exactly the same year/swap you did (minus the headers), but he never really got it buttoned up.

Hopefully you sort out the problem.

I have a feeling the efficiency-oriented Honda guys may recommend you go back to the stock exhaust.

Keep the factory exhaust. Which computer are you using? What kind og O2 sensor??

I am currently using NGK 24300 Oxygen Sensor. 5 wire. the 02 sensor is place near end of my downpipe right below my firewall. The 02 sensor light doesn't come on anymore.
I am currently using a P07- A00 ECU.

I think my hesitation was from a dirty EGR valve. I did clean it up but we shall see once i drive it tomorrow. It revs too high when cold and it still kinda hunts for an idle when I pull up to a traffic light or whenever i stop.

I am slowly putting my car back to stock. I however found and HF exhaust manifold to replace the headers. Today when i filled it up today I got 41 mpgs, which i was shocked beyond belief, because dx transmission revs to high for d15z1 on the highway. In 5th gear I can not go beyond 55mph or ill push myself out of lean burn, so i just sit in the slow lane. I was on the hunt for an HF, which i found one for 65 bucks out of a 91 crx. I just need to find the time and jack to pull it. [/URL]

I posted a short video of my car under my profile.

Let us know what happens with the exhaust manifold and o2 sensor. When I replaced the motor in my HX, I had to replace the cracked exhaust manifold. I used the manifold from a 1999 Civic EX, where the o2 sensor is mounted way down past the engine, right before the cat. The old OEM one I was running gave out on me. The car would not idle and would hesitate while driving sometimes. I bought a cheap aftermarket o2 sensor, and it has been acting up since. It runs fine while not in lean burn. When it tries to lean burn it hesitates and then kicks out. I've disconnected the EGR valve to prevent the car from trying to enter lean burn as a temporary fix. I still get great mileage without EGR or lean burn so it's not a big deal, but I would eventually like lean burn back.

I'm wondering if moving the o2 sensor has any effect on these wideband o2 sensors. The VX and HX both had them mounted right up next to the exhaust ports. I'm curious if moving it away causes a delay in the data, confusing the ECU.

Ill let you know but before I put the hf exhaust manifold. I'm going to put my o2 sensor on my headers. Their are two spots on my exhaust. I can put my 02 where it is or extend it to my headers. It had a spot to screw on the 02. I just didn't do it because of my engine swap and that was the only place it could go was on the downpipe.

These 02 sensors needed to be hot and that's how they regulate fuel economy. That and the hf and vx had the cat right after the exhaust manifold. The o2 sensor has been cut off but the sensor is still there on the hf manifold. Makes you wonder if Honda knows what they were doing and they do. That's why I'm going back to stock. Anyways I'm going you get an extender for my sensor and see if it really matters.

I don't if I would buy a cheap 02 sensor. Stay Away from bosch sensor. These are economy motors . I would get an ngk from ebay. That's what I did. Autozone and o reillys charge 275 for it. I got mine for 120 new. I'm going to mess with my car this weekend.