Newbie question here! I have a 2000 dx, I replaced the exhaust manifold with headers, full 2 1/2 custom pipe, resonator and open mufler, valve job, shaved head, ex intake manifold, msd ignition.
The car run fine for a little bit after the exhaus changed, but keeps on throwing a cel and its not giving me good gas mileage, I have a p28 from another civic I had, should I replace my stock ecu and get it tune?
I change the o2 sensors but I keep on having problems
Thanks for the help

 

You should start by pulling the CEL and diagnosing it.

 

My guess is you're at least getting a code for the secondary 02 because you no longer have a catalytic converter. Pull the codes and report back.

 

No I bet it is a code PO420 for not having a cat on the car at all. Get a cat on the car and have it tuned, not having a cat is not going to gain you much power especially on a Y7 motor even with the mods you have done. But after tuning you will get like 10-15 more whp out of it. Unless you are willing to do some major head work, a big cam and building the bottom end to increase compression you are not going to gain much with a D series. Boost it if you want more power.

 

WHY did you even bother spending that on a Y7 ? you didn't even do a head swap expect to spend 400+ for a car that puts down maybe 100whp if that even(106hp factory rated) so that's probably 85-90 whp for a healthy y7. waste of time/money

 

I got the header and pipe work cause the exhaust manifold broke, all other parts where passed on to me by friends or I bought them really cheap, I have the ecu and wiring harness, I'll rather tune that getting a Catalytic converter and have to pay for extra exhaust work, I'm guessing tuning that ecu will eliminate the second O2 sensor readings, which its the error the ECU keeps trowing

 

I live in S. Florida, parts for civics are really cheap and I got most of them passed on or done by friends!
I'm not trying to have the fastest d series I'm just trying to make the car run fine. without CEL and good gas mileage!
All of my friends are advising on tuning! There's someone that does tuning on crome for like 50 bucks, I'm just asking if its worth to do it

 

I would not do a 50$ tune, that's way to cheap a good tune costs 400+ pull and post the codes