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If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518
Re: $500 to replace o2 sensor???
Originally Posted by mbergthold
I'm working on my daughter's '94 Civic DX coupe, shows CEL 43. Already replaced the fuel filter, seems to have plenty of pressure, so O2's are next. I see the primary O2 in the exhaust manifold, but where the heck is the "downstream" sensor? I've looked underneath, had the exhaust disconnected when I replaced the steering rack, didn't see any wires going to the cat. If it really does exist, a picture would help me a lot. Thanks in advance!
A '94 is OBD1, it only has one sensor.
In the exhaust manifold.
#6
How do I know which engine I have in my 95 Civic hatchback?
The valve cover says VTEC E on it. How many, and what type O2 sensors do I have? I can see the one in the manifold, but have not been underneath yet to check for a downstream one.
VIN# 2HGEH2371SH500106
Ok, so I ordered a new sensor (NTK 24300), mine is a 5 wire wideband type. Installed the new sensor and reset the fault code and the engine light went out.
I drove the car around for a bit and noticed that when the throttle is in a neutral position, meaning not accelerating or decelerating, in any gear, the car sputters and acts like it has a lot of water in the fuel.
It doesn't do this when I'm accelerating or when I take my foot off the gas, and didn't do it before I replaced the O2 sensor. I was thinking throttle positioning sensor or MAP sensor. There is no code coming up, nor is the engine light on.
HEEEEELLLP!
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518
Re: $500 to replace o2 sensor???
Originally Posted by Mike Scott
VIN# 2HGEH2371SH500106
Ok, so I ordered a new sensor (NTK 24300), mine is a 5 wire wideband type. Installed the new sensor and reset the fault code and the engine light went out.
I drove the car around for a bit and noticed that when the throttle is in a neutral position, meaning not accelerating or decelerating, in any gear, the car sputters and acts like it has a lot of water in the fuel.
It doesn't do this when I'm accelerating or when I take my foot off the gas, and didn't do it before I replaced the O2 sensor. I was thinking throttle positioning sensor or MAP sensor. There is no code coming up, nor is the engine light on.
HEEEEELLLP!
I don't have the answers but.....
Did it do this before you replaced the sensor too?
Why did you replace the sensor?
Did you have a fault code related to the sensor you replaced?
If you unplug the sensor and drive it around, does it still sputter?
It did not do this before.
I replaced the sensor because it was throwing the code.
Yes.
Haven't tried that yet.
Tried unplugging the new owner sensor and the sputtering stopped. The CEL is back on, but no more sputtering.
I put about 60 miles or so on it today with the sensor plugged in, the rear gate seals are bad, so I can smell exhaust while I'm driving. It smelled like it was burning richer than with the sensor unplugged.
Not sure what this means or where to go now.
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518
Re: $500 to replace o2 sensor???
Maybe you got a flaky/bad/damaged sensor? Damaged by a box kicker in transit?
If it did NOT do this before and all you did was replace the sensor, it stands to reason you have a problem with the new sensor.
Unplugging the new sensor pretty much confirms it is influencing the symptom, and is the likely cause of the symptom.
Contaminated the new sensor?
No silicone was used near it, perchance? Silicone ruins them in an instant, both by direct contact or burning in the engine. Antifreeze can ruin them too.
Does the EGR system work, is the passage clogged or restricted?
Plugs good, gaps correct?
Maybe you got a flaky/bad/damaged sensor? Damaged by a box kicker in transit?
If it did NOT do this before and all you did was replace the sensor, it stands to reason you have a problem with the new sensor.
Unplugging the new sensor pretty much confirms it is influencing the symptom, and is the likely cause of the symptom.
Contaminated the new sensor?
No silicone was used near it, perchance? Silicone ruins them in an instant, both by direct contact or burning in the engine. Antifreeze can ruin them too.
Does the EGR system work, is the passage clogged or restricted?
Plugs good, gaps correct?
Ill have a look at the plugs and egr system tomorrow.
The new sensor had the threads lubed with some factory anti seize lube covered in plastic. The engine is tight, no coolant leaks at all, so it can't be that.
If you think a good mechanic is expensive, try hiring a bad one
Joined: Dec 2011
Posts: 32,017
Likes: 256
From: Midwest. Aiming about mid-chest
Rep Power: 518
Re: $500 to replace o2 sensor???
Most O2 and AF sensors I see come with a smear of anti-seize on the threads already.
Looks like that particular sensor number (in online Honda parts catalog) is unique to the VX trim, and only non-California cars.
Would be nice to have another car exactly the same as yours to use as a parts swap tester.
On the EGR, the passage all the way through the intake manifold needs to be clean and able to flow as much volume as the valve can flow. If it's restricted and can't flow as much as the computer was programmed to expect, the engine might exhibit lean symptoms at times.
I can't see how the manifold in yours is designed but I suspect its EGR passage exits right behind the throttle body. The opening or port in the manifold may be loaded with soot buildup.
I suspect you got a bad sensor, though it is tough to prove it if it doesn't set any codes.
Maybe you got a flaky/bad/damaged sensor? Damaged by a box kicker in transit?
If it did NOT do this before and all you did was replace the sensor, it stands to reason you have a problem with the new sensor.
Unplugging the new sensor pretty much confirms it is influencing the symptom, and is the likely cause of the symptom.
Contaminated the new sensor?
No silicone was used near it, perchance? Silicone ruins them in an instant, both by direct contact or burning in the engine. Antifreeze can ruin them too.
Does the EGR system work, is the passage clogged or restricted?
Plugs good, gaps correct?
Originally Posted by ezone
Most O2 and AF sensors I see come with a smear of anti-seize on the threads already.
Looks like that particular sensor number (in online Honda parts catalog) is unique to the VX trim, and only non-California cars.
Would be nice to have another car exactly the same as yours to use as a parts swap tester.
On the EGR, the passage all the way through the intake manifold needs to be clean and able to flow as much volume as the valve can flow. If it's restricted and can't flow as much as the computer was programmed to expect, the engine might exhibit lean symptoms at times.
I can't see how the manifold in yours is designed but I suspect its EGR passage exits right behind the throttle body. The opening or port in the manifold may be loaded with soot buildup.
I suspect you got a bad sensor, though it is tough to prove it if it doesn't set any codes.
I really appreciate the replies! This was my stepfather car, he bought it new when it came out, and I've been eyeing it ever since. He always had it professionally maintained, but I can't afford that. It's a beater for me, but a fun one, and I'd like to keep it running well.
I'll definitely check that EGR system tomorrow.
