OT: ODBII PC scanners

[Vic Smith]

That's a heated O2 sensor code. I see with Fords it can be set by MAF and injector issues, and others. Good place to use what you want to use. OTOH, it might just be the sensor. I didn't look into that to calculate the odds. Problem is these sensors can be pricey so you don't want to throw parts at it. Sounds like you're doing the right thing. Getting some new gear too. Watch your prices on sensors if you need one. Last year my daughter's Mitsu threw codes for all 4 O2 sensors. It was a pain figuring out the "bank" and fore and aft because there were about 5 different codes. But I determined that all 4 were tossing a code. Then I just had to make sure the cat wasn't bad, and would destroy 4 new sensors after I put them in. That's why I now own a remote temp reader! Anyway my son picked up the sensors at our local Murrays. You want OEM usually. Murrays usually prices competitively and I don't do much price checking. But since 2 of the sensors were a bill each I went online. Took them back to Murrays unopened. Think I saved about $130 by getting them on Amazon.

--Vic

[Tony Hwang]

Hmm, In that case first thing to do would be reading the output voltages of all O2 sensors. That'll tell whether any one is bad.

[trader4]

That would assume it even has an output voltage or that you knew what the output voltage was supposed to be under whatever the condition was when you measured it.

In the case of the example I gave "left bank oxygen sensor heater", it's about the most clear example of a specific fault that usually doesn't need any further investigation before replacing the sensor. The fault is not about what the sensor is measuring. The O2 sensor has a heater in it to warm it up so that it's operational from the time the engine first starts up from cold. That code means the heater circuit does not have the correct resistance, ie it's open or shorted. It could be a connection/wiring issue, but usually it's the sensor itself that has failed. O2 sensors going bad is one of the most common problems.

You could measure the resistance of the O2 heater after disconnecting it, assuming again you knew what the correct value is. Kind of comes down to how much checking and research you want to do before replacing a $60 part. Also, no need to check all of them. The car could have

4 of them, but the error code is specific as to which one is faulting.

[Tony Hwang]

Can't you go into ECU memory at specific location and read the stored data in Hex usually? You can even fiddle with the value if you want to. You can even dump the cmemory in print form and read the machine code. (low level language) You are right, O2 sensors give lots trouble. So far I replaced them three times on different cars. One knock sensor, one ignition wire. My interest is in things like fuel-air mix. ratio, acceleration rate, relation between gear shift-rpm-speed, etc. Also calculated estimated Hp torque, things like that. Today's cars are more electronics than mechanics. What do you think hot rodders are doing these days?

[gfretwell]

When they first put computers in cars I thought I needed the computer interface to work on it but after 30 years of owning these things, they simply do not fail often enough to justify it and most auto parts stores with scan out your codes for free,

The reality is, cars, compared to the ones I grew up with, are basically maintenance free. You change the oil a couple times a year, replace the tires and throw a battery at them every 5 years or so. They just run and run. You still have brakes and accessories but you don't need a computer for that (once they stopped using that lousy Bosch ABS system GM used in the 80s).

[gfretwell]

Yeah I'm old

[SRN]

Ain't that the truth!! I LMAO when somebody pines for the cars of the 60's &

70's. They were total crap compared to what they build these days.

[Jeff Thies]

O2 sensors are usually no fun to replace, but I did the upstream on the the bank indicated and cleaned the hell out of the MAF. Threw the code again after driving for a while. I'm not unconvinced it's not a DPFE or EGR related.

If I see when it it leans out, I should be able to rule out injectors or vacuum leaks. At least I think so... The code does not tell me enough.

Jeff