b18c99si

my 99 si 18c swap is throwing some codes. the 1st one is the cat becuase im running a test pipe n no cat. the second one is for the primary o2 sensor. n the thrid is for the car running rich or lean. would running a test pipe n no cat cuase this? and my idol jumps from 800 to bout 1500 when starting and then it settles down but sometimes dropping to like 200 or 300 sounding like its gonna stall but never does the idol just picks back up?????

grumblemarc

iTrader: (4)

You answered your own question. OBD2 cars require 2 O2 sensors on a stock ECU.

villc713

Change the first o2 sensor and reset ecu and recheck codes to see what's left

grumblemarc

iTrader: (4)

Why don't you post up the actual CEL codes to we know for certain what we are dealing with?

b18c99si

codes 45, 61, and 67. so try replacing the first o2 sensor and putting a cat on ? the test pipe is from the previous owner. im trying to fix all his mistakes. n yes im new to the honda game so im still learning.

Former User

Reset the ECU to see whether all three codes repeat.

b18c99si

yes its the same three codes its the thrid time i reset the ecu to make sure

Former User

This^

The first issue to address is code 61 for the primary O2 sensor because code 45 and 67 depend on a working primary O2 sensor signal.

B16Riot

if its running rich get a tune.

b18c99si

so ill replace the primary o2 sensor frist. so im i gonna need to replace the test pipe with a cat?

Former User

In CA, yes.

b18c99si

naw im in tx
its running the stock civic si ecu right now should i change that down the line or no ?

Former User

In TX, you may be able to run a test pipe using a secondary O2 sensor simulator. But my recommendation would be that you install a cat.

I believe that you need to install an ECU for the B18, but have the swap experts verify this.

b18c99si

thanks ronj ill look into it u hav any suggestions on which cat i should get ?

villc713

Get a high flow cat online and have it welded up but you may not need it after you change the o2

crawfo661

you can run a mechanical cheat for your secondary o2 sensor to get it to think there is a cat there. There is a thread here somewhere that tells you what to do

villc713

It's called a missing link you can find it on google typing "missing link Honda" you screw that in then the o2

deganjohn

spark plug non fouler and drill out the end.

villc713

Found this on here http://hondamarketplace.com/showthread.php?t=2447783