Here are the codes that came when checked:
0170 - Fuel Trim Malf.
0171 - System too lean bank 1, Sensor 1
0133 - 02 sensor bank 1, sensor 1
0300 - Random/Multiple Cylinder Misfire
0301 - Cylinder 1 Misfire
0302 - Cylinder 2 Misfire
0303 - Cylinder 3 Misfire
0304 - Cylinder 4 Misfire
0420 - Catalyst System below threshold

The car's check engine light comes on after the car has sat for awhile and cold. When you take off from a stop, the car lugs and acts as if it is goign to stall for about 4 seconds. It drives normally after this. As the car warms up the check engine light goes away.

Could the o2 sensor cause all these misfire codes? What is the procedure to check the o2 sensor?

One other thing I noticed was the "flapper" valve on the fuel filler neck is missing. (The part the gas filler nozzel goes into). Previos owner lost the gas cap and said the check engine light cam on after that. A dealer one was installed in its place, but the check engine light still comes on. (It did not hestitate like it does now when the check engine light first came on.)

Car has 89,000 and runs well except for the hesitation at take off. Spark plugs have been replaced, wire resistance checked. Two bottles of fuel injector cleaner have been put in as well as good, high octane gas.

Any help is greatly appreciated as this is an elderly member of the family's car.

 

That may codes sounds like it could be a short of some kind. Check to see if the car has been involved in an accadent before you got it. Also I've seen when there is an internal problem with the ECU it can cause this. If possible clear the codes while driving the car warm and see if any return and record those. Let us see what happens.

 

I know it has not been in an accident because a family member use to own it since new.

I reset the codes after driving by removing the ecm fuse. Then reinstalled it and drive about 20 miles to an autozone who checked the codes. They had all came back.

Can the code for the 02 sensor cause all this?

Could something as simple as a bad cap or rotor?

What should I check now?

I really appreciate any help!

 

very strange. if worse comes to worse, take it to a reputable honda mechanic and get their opinion

 

I am trying to avoid that because of the cost to her.

 

Check out the primary O2 sensor, that's in the exhaust manifold right behind the radiator. Look for loose or corroded connections in the plug right there below the radiator hose. I think it's possible for all this to be caused by a bad sensor or bad connections.

That flapper valve in the gas pipe (if you mean what I think...) won't do anything. It shouldn't keep the new gas cap from being airtight. If that were a problem you'd have code P1456. That thing only prevents you from putting the wrong gas nozzle into the tank (like diesel fuel)...

 

I have wondered. ANother tech told me it could not be caused by a bad o2 sensor but I wondered if it could. But if it was this, why does the car get better after it is warmed up and driven a little bit.

Do you know the procedure to check it with a multimeter?

 

I don't know right now which color wire is the signal, but you have to measure that with it connected & the engine running. If the sensor & everything else is good, it will quickly oscillate, centered around 0.5v, like maybe from 0.2 to 0.8v. Many DMM's cant read that fast & an oscilliscope might be better...

Best thing is if you found a rusty connection or a broken wire. Then just fix it, reset your ECU, & see if some of the codes don't come back. Or maybe just replace the O2 sensor, since 89k miles isn't a horribly bad lifespan anyway...

 

I would but it is 90 bucks. I hat to change it if it is not bad. Cant you check the resistance of it somehow?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ashleeb &raquo;</TD></TR><TR><TD CLASS="quote">Cant you check the resistance of it somehow?</TD></TR></TABLE>It'll read open-circuit unless it's hot. The only way I know is what I said above. It's a voltage reading, not a resistance. Besides, P0133 says it's sluggish, not high or low.

If the sensor heater was broken, THAT's a resistance measurement between the 2 black wires on the sensor. Between 15 to 40 ohms. But that would throw different codes vs. the ones you listed. (P0135 = primary O2 sensor HEATER)

 

to anwser your question it is very unlikely that your O2 sensor can cause all them codes you should check your ecu and check your timing. if worse comes to worse bring it to honda.

 

When my O2 sensor was going bad, my car ran like utter crap until it warmed up. At first it was just a slight stumble, then progressively got worse. The check engine light would turn off occasionally on its own, but the next day it would come right back on. After the car had been warmed up, it ran fine.

After putting a new O2 sensor in, the car perfectly again.

btw, the only code I got was for the O2 sensor...

 

The signal wire for voltage is the white wire. See what your getting. Also the autozone code scaners taht they have will some times pull codes that are not really there. Run into that all the time. And yes I work at a dealer.

 

Take the car to the dealer pay them $70-75 for them to check it out. That way you know what codes are really there.

 

How do they pull codes that are not really there? Seriously , I was debating buying one of those scanners but if they do that I am not so sure I want to shell out 200 bucks for it.

So there should be 12 volts coming out of the white wire? measure this wire at the connector that goes into the oxygen sensor (plug)?

I am really interrested in learining this.

Do you think an o2 sensor will fix the stumble on take off even if it does nothing for the other codes?

Is there an easy was to check the catalytic converter?

 

If you trust the codes so far, you already have one for the O2 sensor (P0133).

Get a new sensor, I'm guessing that at least SOME of the other error codes will dissappear. If your P0420 disappears, then your converter is OK.

 

Can an 02 sensor cause this stumple from a stop? It is worse when completely cold so much so that it will almost stall. Gets better when it warms up.

I thought that when cold it runs in open loop mode and the o2 sensor is ignored anyway?

So I should not trust those codes?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ashleeb &raquo;</TD></TR><TR><TD CLASS="quote">Can an 02 sensor cause this stumple from a stop? It is worse when completely cold so much so that it will almost stall. Gets better when it warms up.

I thought that when cold it runs in open loop mode and the o2 sensor is ignored anyway?</TD></TR></TABLE>Yeah, that's right about open-loop, but that doesn't last very long. A minute or so? You have so many codes that maybe some of them would send you on a wild-goose chase.

You said you checked the resistance of the plug wires. Have you checked for arcing? Wires can fail 2 different ways - bad resistance or bad insulation. Start the engine cold, in the dark, look for a dull blue glow around the wires.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ashleeb &raquo;</TD></TR><TR><TD CLASS="quote">So I should not trust those codes?</TD></TR></TABLE>Turbowa's note is the first I've heard about reading incorrect codes, but maybe???

 

But isn't that code for a "slow" sensor? Not neccessarily a bad sensor?
I know that sensor is 90 bucks at autozone.