Need 02 sensor. Suggestions for fast shipping?

familyman · 2023-09-16T04:06:50+00:00

Rego is due on the 25th and the oxygen sensor just died. Will that cause a pink slip/roadworthy test fail? The sensor is listed on ebay. But they told me...

familyman

ramrod Which car?

1991 240

Why would the o2 sensor cause you to fail the pink slip

As I said, I wasn't sure if it would or not. I don't pay much attention when they do a pink slip, because usually I've already gone over the car and fixed anything that wasn't working. (I thought they might test the exhaust.)

ramrod

I see.

What makes you think the sensor is faulty?

And no, it is not a safety concern nor does any mechanic test exhaust emissions in nsw for a pink slip (that I have witnessed)

familyman

I've replaced it once before about 5 years ago I think. It's dash light is on plus I can smell it's running rich. I only do occasional short trips too, meaning the muffler doesn't get a good burn-off. It could be something else but it just feels like the O2 sensor again.

ramrod

It’s a better idea to diagnose first to be sure, as you wouldn’t be happy if that didn’t rectify the problem

Some basics first, how does the car drive? How much fuel does it use? How is the idle?

timbo

Can you read the fault codes? 1991 should be lh2.4

familyman

timbo Can you read the fault codes? 1991 should be lh2.4

Yeah I'll have to look up how to do that again.

familyman

It drives fine apart from hesitation when you first give it throttle. Not really sure on fuel usage, but I've always thought it was a bit thirsty on fuel compared my 1978 244. Idle is fine. As I said it does hesitate a little, like when first moving off from traffic lights. Every car I've owned has done this though... that flat spot you get where you have to lift your foot back off otherwise the engine wants to stall - then it's fine once you start moving/accelerate more. That only started when I had to start keeping it outside under a tree because the real estate agent won't fix the garage roller door. Most cars I've owned have done the hesitation thing. It tends to disappear once the engine has warmed up. Oh and I was thinking today the oil needs changing. It's been in there well over a year. Bad health has prevented me changing it. I was thinking today that is probably what has killed the O2 sensor. I don't drive much either. About once every 3 weeks on average, and 98% of the time it's 8km then into the supermarket for a couple of hours (so the muffler only starts to get hot then cools down again). Then 8km back home. It's probably not enough for the exhaust system to get hot enough.

Major Ledfoot

familyman
https://www.volvoclub.org.uk/faq/EngineOBDCodes.html
LH2.4 is same same

ramrod

It sounds like it needs a good long drive.

Short trips are no good

Also the o2 sensor can be tested

Where abouts is the car at?

jamesinc

A '91 shouldn't hesitate at all, you should be able to just give it throttle and it takes off.

beez

GUYs, I know this is an OLD post but save yourself some money and know this hack….

The O2 sensors fail a lot of time because of the carbon build-up ON the sensor.

Take this thing out of the vehicle and wire brush the whole thing. Put it back in and IF you have a OBG2 reader clear the code for the bad 02 sensor. If not, drive it for some miles and the code will clear. NO NEED TO BUY A NEW EXPENSIVE SENSOR.

familyman

beez All O₂ sensors I've seen over the years have a cylindrical stainless steel outer casing with holes that allow exhaust gases to reach the actual sensor which is inside. Also the sensor itself has a special coating. So even if you could reach the sensor itself, wire brushing it could damage the coating so it may no longer detect oxygen levels correctly, throwing off the fuel/air mix. If brushing the outside worked it must be because only the holes in the outer casing were blocked, and the sensor inside was okay. To try and save some money I've seen two different mechanics heat them with an oxy/acetylene torch until red hot to burn the carbon off, and people on youtube often spray or submerge them for anything from a couple of hours to a couple of days in everything from brake cleaner, to carby cleaner, to acetone. But doing this can damage the sensor coating too. That's probably not a big deal with an old 240 but I imagine computers in newer cars wouldn't like it much. Mine is offline again right now. I don't have an oxy set so I'm going to try brake cleaner. If that works I'll make sure I always have a clean one ready to swap in. For people who have to pay a mechanic it's probably better to just fit a new one. We can't see inside it to know if we've cleaned it well enough, or only taken a little carbon off. (So it could go offline again in a few weeks and have to pay twice.) May as well just buy a couple ready when they're on sale. e.g. I think ebay currently has some discount code if buying auto parts. I might even do that instead myself.