False o2 code?

[acurac27a]

My ECU keeps giving me a front o2 sensor code and putters and pops. I unplugged the front one and the same thing, unplugged the rear one, same thing, unplugged both and it runs fine but still gives me a front o2 code. I replaced both sensors with new ones and it still doesnt work, with both unplugged it will run pretty good a few miles then it hesitates alot unless i let off the gas and hit it again quick.. unplugging the fuel pressure regulator makes it run alot better but after a few miles it loses alot of power and feels more like a 4cyl than the v6 it is

I have a aftermarket intake so i dunno if maybe its making it run too lean or what? exhaust pops with be a indication of a lean mix right?

[CivicSpoon]

When the exhaust backfires, it means your car is running too rich. This would also explain why your O2 sensor went bad. It sounds to me like you're running way too rich. Have you cleared the check engine light code for the O2 sensor and have it immediately come back, or did you not reset it when you put the new sensors on? And what upgrades do you have, that you need a fuel pressure regulator?

[acurac27a]

yea i did clear the code and the fuel pressure regulator is stock. its not back firing, I heard from a mechanic once that popping was from gas not completley burning in the combustion chamber and goes into the exhaust manifold, the next good combustion ingnites it and causes a small explosion or compression within the exhaust its self.. not too sure on this since its just word of mouth but i do know theres a difference between backfiring.. back fire happens when a piston has not made it past TDC and fuel ignites, the piston is pushed backwards and often bends/breaks rods, pistons and cranks.. not good at all..

I heard popping can come from either too much or too little fuel.. so i unplugged the pressure regulator to give it maximum fuel pressure all the time and there has been no popping what so ever since then so i'm going to have to assume my o2 sensors or ecu is leaning out the mixture too much..

The only mods i have is a short ram with a ram air duct and a high flow cat, the car fan perfectly fine for months with those mods before this happend. the car sat for like 2 months after it hydrolocked and i've had alot of problems since then.. the engine is good, 180PSI on every cylinder and it runs perfect up untill it warm so i'm going to have to assume its electrical. I've tripple checked all connections and checked for vac leaks

What i really want to know is if anyone has ever had or seen a false o2 code and what did they do to fix it? i'm 100% sure the o2's are good and that they are getting power.

[superbluecivicsi]

make sure there are no exhaust leaks and put a multimeter to the wires. you replaced the sensors with a direct plug in o2 sensor o a universal splicable o2 sensor?

[acurac27a]

its universal, only 1 wire.. i'm pretty sure they are getting power, if i plug either one up at the same time or seperatly the car bucks and pops like crazy, so its clear that there isnt a break in the line.. the 2 original ones i knew were good cause i replaced them a couple months ago, and its the same problem with the 2 new ones i put on there..

my tach is starting to jump up 3,000rpm very quick and back, kinda like a bad spedo cable but it only goes upwards from what its at, never down.. so i'm gona replace the coil and the ECU since i can get them pretty cheap and see if that will help the problem..

[superbluecivicsi]

who cares if its actually getting power. what are the actual voltage readings and does it have contituity?

[hxgaser]

Too much fuel or rich mixture can fowl-up your O2 sensors, and yes within 2 months. Anyways, you said you took the fuel pressure regulator out? And before then it was making popping noises? And you rebuilt the motor sometime ago right? Well, you might want to check a couple of things. First, hook everything back up. Start the car and let it warm up to normal temp. While running, get a can of WD40 or carb cleaner. Spray it lightly around the intake to throttle body connetion, and intake to head connections. You are checking for a vacuum leak. If your RPM changes noticibly, then you have a vacuum leak. Depending on where that is, you might have to pull the intake to replace the gasket.
If that checks out fine, then I think you might have a timing problem, and it might just not be the ignition timing. When you rebuilt the motor and set the timing belt, did you make sure everything (CAMs, and CRANK) lineup properly? Off lined cams cause timing problems. Your ECU might be over compensating to correct the lean or rich condition caused by the cam alignment. A few degrees of cam misalignment will still fire the car, but it will run like crap.
I hope it's not the crank timing. Anyways good luck.