i did a mpfi swap on my 89 sedan and ever since then i have been running extremely rich. i can smell gassy exhaust and the CEL comes on for the o2.

its a b2 bottom end with a y7 head on it. its all stock besides aem fuel rail and a light weight fly wheel. ive checked the ohms on the injectors and they all read 2.5 ohms. i replaced the MAP sensor 2 days ago and that has seemed to help but the CEL has came on once and i can at times still smell gassy exhaust fumes.

any ideas on things i can check or do????

 

What injectors are you running?
Have you tried a different O2 sensor?
Have you checked the O2 wiring?
What code # is the CEL giving you?

 

- injectors are stock si injectors
- havnt tried diff o2 yet but will be doing that soon if i cant get something figured out. it was fine before i did the mpfi swap
- havnt looked at the o2 wires cause i never messed with them.
- code #1 for the o2

 

anyone else have suggestions?

 

Fix code 1 -- the O2 sensor plays an important role in the ECU determining the proper fuel trim.

 

i dont think a 1 wire o2 does that much does it?

 

What makes you think this^?

The O2 sensor's sole function is in the control of fuel delivery to the cylinders.

 

cause its just 1 wire. i know the 4 wire o2s in the obd1 rely more on it than the obd0. but i will change it out and see. im not saying the 1 wire o2 doesnt do a lot, i just havnt had that much experience with them to fully know.

 

plus the o2 CEL never came on before i did the mpfi swap. i did have a misadjusted TPS messin things up too. (i didnt adjust it, someone else who thad the TB before me did it) so i suppose that coulda made the o2 go bad.

 

Fix code 1 and your engine should not run as rich and the problem may be fixed.

 

lol im trying to fix code 1. my thinking is something else is making the engine run rich making the CEL to come on, rather then the o2 being bad makin the CEL come on and running rich.

 

If you think the O2 sensor is good, then check the O2 sensor wire for a short or open.

 

only reason why i think its still good is cause it was before the mpfi swap. i will change it out tho.

what about possibly a clogged cat? cause i do get a lot of exhuast fumes in the car but it dont appear i have any exhaust leaks.

 

It could be a leaky injector.

Still, check the wiring for the O2 as well as try a new O2 FIRST

 

well i went to replace the o2 and found that the o2 wasnt even finger tight on the exh manifold. go figure.

it appears i am trying to still fix errors the previous shop has done to the car. the o2 was a replacement o2 so i put in a oem honda o2 that i had from my hatch and i made sure it was tight.

i havnt drove it since i got the tightened o2 back in. ill let you know when i find out.

 

make sure you do have the resistor box wired up properly.

 

changin the o2 didnt do anything. had a CEL come on literally like a minute after i got on the road heading home.

next ill be checking the wire that goes from the o2 to the ecu.

i have double checked the resistor box prior to this. i had a bad injector when i did the mpfi swap so i had to double and triple check my wiring on that.

 

got the problem mostly figured out.

the ecu ended up being chipped when the guy that i bought it from swore up and down that it was stock. i took the cover off and it was clearly chipped. but i still had a problem when i put in an actual stock ecu. the car wouldnt rev past 3000 rpm.

that problem is now fixed as well. the 2 wires for the crank angle sensor were backwards so a simple flip around and it was fine after that. only thing now is my timing is off. must be a tooth off cause its close to being timed but i have the dizzy turned all the way . will be doing that later today after my car gets done with its allignment.