I have a 2006 Accord 2.4
I've had a check engine light and the code suggested maybe the cat is out of spec. Time for a smog and I really want to see how far this car will go. It has 320k and running like a champ until..... With the cost of new cats, I can't justify keeping it going. Saw youtube trick. Put a gallon of lacquer thinner in half a tank of gas and drive it. So I did and the car ran great. all the way to empty. Checked the code and found the O2 upstream fail. That's better than the cat code. Car was running fine the next day and I ran it til the fuel warning light went on. Made a quick stop and when I got in it ran like sh**T!.. no power but I was able to drive straight to the gas station and filled it up but no change. Checked the code and got knock sensor fail. Replaced the knock sensor and now I only have the O2 code but still runs with bad power. I know the code erase means some of the sensors need miles on them to report but I would think it runs so poorly there must be another code.

I don't think the O2 sensor would affect performance this way. Am I right?

I think it may be time to pull the cat and see if that restores power (cat is plugged right?)...but it ran so well up to now that I am stumped...

Does anyone have any suggestions? Thank you in advance

 

Can you please tell us the actual code numbers for each place in your post where you mention a code?

For example, there isn't any code for "O2 upstream fail". There are several error codes for the first O2 sensor, and none of them are guaranteed to be a failed sensor. It might be the signal high, signal low, or heater circuit, or ???

 

Thanks for responding I wasn't with the car at the time.
The code that I am getting is P0135. The car starts and idles poorly under 1k RPM. When I apply gas pedal, it slowly winds up to speed but clearly no power. Got onto the freeway and 80mph but....
I don't recall the knock sensor code (now gone).
I do have experience cleaning out the oil screen. When that was the trouble, the car would run and at certain rpm would cut out. Very different this time around.
All help is appreciated. I have access to the car and I will be able to spend time on it this weekend so am hoping to have a few things to try. I do have a replacement upstream O2 sensor but have not put it on. I had replaced that 2 years ago for last smog test so seems odd that it has failed. (I know that is possible if I don't use OEM but I don't recall what I used)

 

Hey Jim,
It was heater circuit. I do appreciate your first response and am hoping for further help or suggestions.

 

I would start by visually inspecting the o2 connectors/harness.
I would next refrain from putting paint thinner in my gas tank. How that might clear out a cat is beyond the scope of my knowledge, but passing through the engine it will have been burned, so unless the gases are corrosive I don't think it would do much.

Its possible you damaged your o2 sensor, or maybe it was just a coincidence that has accompanied the excess driving done to burn through the fuel you had left.

The internet is a cold mistress, that can't always be believed. At one time in the past I had convinced myself via the internet that Di-lectric grease is the best invention on earth, until it became the bane of my existence because some had gotten between the contact surfaces of multiple power and ground connections.

 

given the mileage and the fact that it's gotta pass smog, plus I've got the backup identical car I've been driving, I figured it was worth a try. And now I'm curious to finish it out.. so are you saying the bad O2 sensor could cause this horrible power loss? I'm short on time theses days but I'm gonna go ahead and swap in the new one and post a status. Thanks for your input and my ears are wide open..anything else you would try?

 

Hey Jim,
I replaced the upstream O2sensor and cleared the codes. Ran the car for a while and no codes so far. Still very poor power. I used an infrared thermometer at the bend of the pipe before the cat and got about 250 degrees. At the flange in front of the cat I get 460. At the rear flange I get 560. At the pipe between the cat and the rear flange I get 580-600.
Is it odd that there are no codes? The P0135 would come up right away but now stays off. I don't think I wanna drive 50 miles for all the sensors to activate. Ideas?

 

I think you should pull the catalytic converter and look inside to see if the comb is messed up and causing a blockage.

 

Sorry, I haven't been on the site for a few days...

I agree with PA those temperatures seem too high and it would be a good idea to verify the catalyst isn't damaged.

Lacquer thinner is a strange cocktail of stuff, and I'd be afraid to recommend anyone putting that in their car. Damage to the sensor itself would set another code, not P0135. But I would not expect any magic snake oil to fix a broken preheater. The error code doesn't really indicate the sensor function was bad.

No error codes now, right? Blockage in the catalyst sounds like something you want to check out (hope it's not, but....).

 

What kind of mileage did that half tank of driving get you?

The gas station you used to refill, is it one you have gone to before? I ask because considering you drive a bunch maybe you just got some bad gas. I live in socal, and while not often, I've several times ran across a station who gas seemed to be old or otherwise contaminated with moisture. Isnt typically an issue unless say you come in with an empty tank and leave with a full one. Not just small name places either, the Arco closest to my house is a frequent offender, I notice when it rains they put sandbags and tarps over the access holes in the ground.


Did a little searching and it seems rockauto has "affordable" carb compliant cats that are bolt on replacements with no welding required. But they still run 400ish bucks. My 94 accord needed a cat 3 years back, and it ran me like 500ish down here near port of Los Angeles.