Oxygen sensors?

dannmarr · #1 03-21-2012, 10:28 AM

I got code 37, driver side 02.
I noticed the power steering was leaking and the 02 was wet.
So I replaced the rack and the 02.
Now I get code 32 and 37, both 02 sensors?

I have been getting hesitation on low RPMs uphill
I also noticed the engine wants to stall at idle
I've been having loss of power on take off
I noticed the main ground wire is not connected to the firewall,
but it was reconnected to the Trans top bracket? Is this ok?

The recent things done: Trans swap, fuel lines above gas tank, rack and 02 sensor

Any ideas? Please help! My mechanic wants to replace all the coils!

icingdeath88 · #2 03-21-2012, 10:58 AM

It should never be necessary to replace all the coils. Only the ones that are actually bad. Mechanics that do that want to fix the coils with certainty, so that customers don't come back if another one is also bad and think the mechanic is screwing them over. Coils are not very cheap for these cars.

First do some diagnostics. Unplug the MAF (before starting the car), and see if the car runs better with the MAF unplugged. Hesitation and stalling can be MAF related symptoms as well, and this is a very easy test.

If you're getting O2 sensor codes, then that can mean either that the O2 sensor is getting an out-of-range reading, or that it's actually bad. O2 sensor codes do not automatically mean that they need to be replaced. They can throw a code if the car is running lean, and there is excess 02, or if one or more cylinders isn't getting spark. No spark = O2 and fuel in the cylinder didn't combust, and the O2 sensor is detecting excess O2 as a result. So a coil or 2 is a possibility, as is a spark plug or two, wiring to them, or bad grounding to the engine. (And other things, these are just what seem related based on what you said).

Check the grounds. The battery ground in front of the battery, the engine ground kind of near the starter, and the smaller ground near the dogbone mount. If you want you can also add another ground - more grounds never hurt anything.

Also check the air filter to make sure it's not super dirty or something.

"fuel lines above gas tank" - If the engine is not getting enough fuel like the fuel filter is clogged or something, then that could cause low power and hesitation as well (and O2 code). Might be worth exploring, but check the other things first.

Wikedjuggalo · #3 03-21-2012, 11:18 AM

What brand of O2 sensor did you get?

dannmarr · #4 03-22-2012, 04:28 PM

OK, I unplugged the MAF and started the car. It lasted for about 10 seconds and then it stalled. What does that mean?
One other thing comes to mind, the mechanic sprayed some dielectric spray into the connectors of the 02 sensors, the good one and the new one.
Would this cause anything?

svxcess · #5 03-23-2012, 05:17 PM

Quote:

Originally Posted by Wikedjuggalo

What brand of O2 sensor did you get?

I have always used the NGK/NTK direct plug in. They have lasted longer than most.

http://www.amazon.com/NGK-24614-Iden...ar=1&carId=002

Less than $38.00 each and free 2 day shipping with Amazon Prime

dannmarr · #6 03-23-2012, 07:41 PM

I used the direct plug-in by Walker 02 sensors.

dannmarr · #7 03-24-2012, 01:00 PM

I'm going to do the spark plugs next, they are due. I already printed up the 'How to' change the spark plugs. Anything else I need to know?

alia176 · #8 03-27-2012, 02:16 PM

Quote:

Originally Posted by svxcess

I have always used the NGK/NTK direct plug in. They have lasted longer than most.

http://www.amazon.com/NGK-24614-Iden...ar=1&carId=002

Less than $38.00 each and free 2 day shipping with Amazon Prime

Dang, that's a good price and free Super saver shipping too. Nice. I need to go find out how many O2 sensor my '92 has( two or three)!

92snowmachine · #9 03-27-2012, 02:31 PM

you have two. the obdII cars have three.

92snowmachine · #10 03-22-2012, 04:55 PM

Quote:

Originally Posted by icingdeath88

It should never be necessary to replace all the coils. Only the ones that are actually bad. Mechanics that do that want to fix the coils with certainty, so that customers don't come back if another one is also bad and think the mechanic is screwing them over.

a lot of that is how labor times are booked. most cars pay a certain time for 1 coil and add .1 for each additional even though it's a ton more work. it saves money in the long run because the initial coil covers most of the labor cost.

you shouldn't spray dielectric grease into o2 connectors, it can give you a bad connection. i would clean it off.

1986nate · #11 03-22-2012, 05:02 PM

Any idea when the Coolant temp sensor was last replaced? Have you ever had "hard starting" issues?

When were the spark plugs done last?

icingdeath88 · #12 03-22-2012, 05:55 PM

Unplug the battery for 10 mins and try the maf unplugged again. Sometimes it stalls and I'm not sure why. Also try giving it a little gas to keep it from dying and then let it warm up and see if it will idle then.

Subix · #13 03-22-2012, 05:56 PM

Just to throw my .02 cents in, I had the same problem as this before and replaced both sensors and was still getting both codes thrown as well. Within a months time I started getting xmas lights on the dash which means my alternator finally kicked the bucket. After I replaced my alternator the codes for both o2 sensors being thrown went away.... so I pinpointed a faulty alternator as the issue for throwing both codes on new sensors with wonky voltage spinning the system for a loop somehow. This may not be your issue but it's worth testing it just in case.

dannmarr · #14 03-22-2012, 06:40 PM

Thanks for the responses!
I don't have trouble starting. I never had the temp sensor changed.
About the alternator, when I'm at idle the voltage drops bringing up the dash lights up so slightly, you can only see it at night. Then the engine revs and it goes away. It doesn't happen all the time.
The spark plugs were done about 50k miles ago.
I'll try unpuging the battery and the MAF.