Sprockets

iTrader: (6)

I know this is long, but please take the time to read through it for me. Thanks!

It's inspection time, and this is my first year running a 3 bar map sensor. I replaced my 750cc injectors with 310cc, put the catalytic converter back on, and swapped the Hondata and P28ecu with my stock ecu and Greddy blue box (I know it sucks, but I can pass inspection with it ). I stupidly forgot to unplug the 3 bar and replace the stock one!

I started the car, and it was unresponsive and refused to idle. I thought maybe my fuel injectors were stuck, which happened to a ruined set of RC310s I had last year. So, I revved the engine over and over, just enough to keep it running. I had to restart it about 10 times before finally giving up after the CEL came on (Code 65: Oxygen Sensor Heater (Secondary) malfunctioning or defective oxygen sensor heater). At the time I was pretty certain that it might have been the injectors again. The car was in the garage, and there was black soot and water sprayed all over the wall and floor.

The next day, I yanked the 310 injectors and sent them away to be cleaned and flow tested. Everything else was returned to the way it was before with the exception of the catalytic converter. My Apex'i air/fuel meter (yeah, I know it's not accurate) would read 20:1 about 90% of the time. At night time I can see smoke coming out of my exhaust highlighted by other people's headlights while I'm accelerating, even slowly. There are black specks on the back of my car. Today was the first day I drove it in freezing weather. I've been keeping the revs low. The heater control was turned all the way cold until the car warmed up, then I turned the heat on, the coolant temperature dropped, and shortly after that I got another CEL (Code 43: Fuel Supply System defective or malfunctioning fuel supply system).

At this point, I'm assuming it's the O2 sensor. Would you agree? I ordered a new Denso O2 sensor the other day, but in the mean time, is there an effective way to clean a fouled O2 sensor? This sensor is only about 6 months old, and used for approximately 7000 miles. It's also a Denso. Thanks for reading this, and I'd appreciate some help.

Sprockets

iTrader: (6)

I guess that was too much detail, lol!

nsxmatt

You can use gas to clean it, worth a shot.

Sprockets

iTrader: (6)

Thanks, I'll give that a try. I searched the archives, and found torching gently works sometimes.

BigMoose

I searched and can't find my old post... maybe I did it on another board. Here is a trick that sometimes works. Pull the sensor, power the heater. This prevents severe thermal shock. Take a small propane or butane torch and roast the tip gently like a hot dog. Keep the deep blue tip of the inner flame about 4mm from the metal shroud. this will give an oxidizing flame within the thimble to help cook out contaminants. Sometimes works. Be gentle, turn the sensor often. Gently heat, you don't want a severe thermal shock to it... it will crack.

Sprockets

iTrader: (6)

Hey BigMoose,

Your posts were the last ones that I ended up reading. They were at the very end of all the posts in my search, but they're still there! Two things I'm not sure about:

Is this suitable for heating the element?

No, I don't use it to smoke crack, lol.

Could you please give me details about a safe way to power the heater? Thank you!

BigMoose

This may or may not be too helpful. I use the rack of power supplies pictured at the left to power my experiments on oxygen sensors. They are lab supplies 0 to 50 volts and current controlled. Most likely you don't have those. As long as it is a 4 wire standard oxygen sensor, and the heater measures around 6 to 12 or 15 ohms you should be ok just using your car's battery voltage, you won't need the alternator running. As usual, use common sense, so you do not directly short circuit your battery thru the clip leads.

I take a couple of clip leads and hook to the pins. I have a drawer of miscalaneous pins, in the second figure, that I just slip over and clip to. Not having those you might use some brass or aluminum thinwall tubing from a hobby shop, that you judicously crimped to fit your pins nicely.

The third phot is my butane torch used to revive a sensor or two. Good luck!

Sprockets

iTrader: (6)

That's good info! Thanks again.