1998BlackPlasticToy

Are heated oxygen sensors going to plug into my car and work?

98 C-5

Bill Curlee

I dont understand your question. All four of your OEM O2 sensors are HEATED Sensors. The rears have a different connector than the front and a larger heater core. If you examine your sensors, you will see that they are FOUR WIRE sensors.

What issues are you having?

What DTCs are being displayed on the DIC?

Bill

1998BlackPlasticToy

My O2 sensors have only been lasting a few months. Engine is blown, cammed, full length headers. Problems have only been since adding the blower.

Codes: P1133 HO2S Insufficient Switching, and P1153 HO2S Insufficient Switching

All O2 sensors are heated but there's a difference between "heated" and "un-heated" in the parts catalog:

"Heated oxygen sensors have an internal heater circuit that brings the sensor up to operating temperature more quickly than an unheated sensor. An oxygen sensor must be hot (about 600 to 650 degrees F) before it will generate a voltage signal. The hot exhaust from the engine will provide enough heat to bring an O2 sensor up to operating temperature, but it make take several minutes depending on ambient temperature, engine load and speed. During this time, the fuel feedback control system remains in "open loop" and does not use the O2 sensor signal to adjust the fuel mixture. This typically results in a rich fuel mixture, wasted fuel and higher emissions.

By adding an internal heater circuit to the oxygen sensor, voltage can be routed through the heater as soon as the engine starts to warm up the sensor. The heater element is a resistor that glows red hot when current passes through it. The heater will bring the sensor up to operating temperature within 20 to 60 seconds depending on the sensor, and also keep the oxygen sensor hot even when the engine is idling for a long period of time."

Dcollins3208

Check your O2 fuse. Had this problem a while back and ended up being a wire that kept shorting on one of the o2s

XotiK ZO6

I have had these codes since adding LT's. They do not cause any issue and are a PITA.

I have read that these could be tuned changing the reference voltage with HP Tuners and a wideband sensor. However, they can be set not to trigger a code.

lionelhutz

Other than the codes, are you having other issues with the car?

I believe you need to just turn-off those codes.

1998BlackPlasticToy

Gas mileage went from 24 to 16 MPG!!
Don't care about the codes. Just want the gas mileage back. High test is cheap now, but not always.

No place close to change the tune.

Does anyone know where the O2 fuse is? Kick panel or under the hood?

Thanks,
Arden

Gordy M

It sounds like you have a few more problems, have you ever ran a scan log or know a friend who has scan/log capabilities and can check what your fuel trims, O2 switch points, timing, etc. Are you running a speed density tune, custom operating system, etc. Are you using a MAF sensor as part of your tune? Do you have CATS or are they removed. These are just some of the areas you need to have answers for to find a solution for your problem rather than putting bandages on areas of the problem.

Without adequate information, you will be chasing shadows, off hand you are probably running pig rich and fowling your sensors. You can tune out the rear sensors--normally done with headers--since they are only used at start up and to make sure there is a heat drop from what the front sensors are reporting. Other options are using the rear O2 sensors in the front--with pig tail wiring harness.

If you can get adequate scan/logs of 20 minutes or more using some performance PIDs, you will get some excellent help in finding your solution.

1998BlackPlasticToy

Thanks. You have given me quite a few things to check out. I'll contact my tuner and see if he can help.

Arden

Bill Curlee

WHAT KIND OF TUNE DID YOU GET? In the shop tune or a mail order tune?

If you get the PCM retuned, I would pop in a new set of O2 Sensors. Yours are most likely fouled and not accurate.

If it were me, I would use this schematic and do some voltage measurements and make sure you have good sensor HEATER VOLTAGEs . Check directly on the OXYSEN Fuse:



Sometimes the Splice pack gets correded and causes a poor ground.. Either way the heater has to work for the sensor to be stable.

Bill

Bill

1998BlackPlasticToy

Thanks Bill!! I will check out as much of it as I can before I take to the shop to have the new sensors put in.

Had it tuned on a dyno by the blower installer. I'm sure it's good, though I'm going to check and see if he turned down some of the levels that people have suggested.

I'm sure the sensors in there now are fouled. They worked for a while. Hopefully the heated sensors will last longer / work better.

Arden

1998BlackPlasticToy

Can you tell me where the splice pack is located?

Thanks
Arden

lionelhutz

There is a ground splice pack down under the battery. A bunch of black wires go together into it. It's similar to the ones by the hood hinges but it doesn't have the ground tab, one of the wires going to it is grounded.

Bill Curlee

EXACTLY! Its Taped to one of the larger harnesses. There's a white cap on the end. Pry it off and use a pair of needle nose pliers and pull out the ground bar. If it corroded just clean it all up and reassemble.

Here's a really really bad one. It was exposed to battery acid. I've seen TWO like this:



Make sure that the female pins are not spread apart!! They need to make good solid contact with the male pin.


The pin on the bottom row far right is badly spread!!




Cleaned up:





Hope this helps...

1998BlackPlasticToy

Yes, very much. Thanks!! Now I know what to look for... And do.

Bill Curlee

You need to DATA LOG your PCM / Engine.

Figure out what your Long Term Fuel Trims are. If there significantly POSITIVE, you are fouling out the O2 Sensors.

You also need to use a DC Volt Meter and check the supplied voltage to the OXY SEN fuse. There are two test points on the top of each fuse Measure that point to chassis ground.

What is your idle AFR, cruising AFR and Power Enrichment AFR??????????????????????

Bill

1998BlackPlasticToy

I can check my voltages w digital vom but have no access to data logging equipment. I don't know the AFR's at various points; I have to trust my tuner set them correctly and nothing has changed since he tuned. I'm sure the current sensors are fouled; that's why I'm changing over to heated ones. I've been getting 24 mpg, so I have to think that they are set correctly.

I've not been driving / running hard lately, trying to baby my clutch till I can replace it with one suitable for the HP/TQ I'm putting out now. I'm sure that short, local runs are contributing. Guess I'll have to take some spins down the interstate to clean things out...

Thanks for all your suggestions.
Arden

Bill Curlee

Arden

Regaedless of a PERFECT TUNE or NOT,,,,,,,,,,,,, Something has changed to make your PCM NOT HAPPY!

FIND, BEG, BORROW, some Data Log hardware.

Anyone with HP Tuners or EFI Live can do it for FREE....

Some Data Scanners (Actron) (Sold at Autozone) can monitor LIVE Sensor Data and show you O2 Sensor data and LTFTs along with any other SENSOR Live sensor data and tell you whats not HAPPY.

If your going to own a modern EFI vehicle,,,,,,,,,,,,,,,,,,,,,,, You will have to be able to monitor ALL the stuff that allows the engine to work with the PCM.

Other wise,,,,, Carry a TON of cash in your wallet for the Shops to do it for you..

BC

1998BlackPlasticToy

OK! I hear ya, loud and clear. I'm going to see what I can get; I agree with you. If I'm going to have a high performance vehicle, I need to have the tools to keep it running and know what's wrong with it. I appreciate your help. I'll keep you posted.

Arden

1998BlackPlasticToy

Ok. I'm looking at Actron scanners. I found one that's very reasonable priced and here's some of the stuff it does:

LIVE real-time data, over 300 possible data PIDs available depending on vehicle
Over 15,000 generic and manufacturer specific DTC definitions
Reset MIL and turn off Check Engine light
Backlit display
Read and display LIVE engine data
Displays OBD II generic and manufacturer specific definitions on screen
Read and display MIL status
Read and erase DTCs
Tool gives visual indication when the trying to communicate and retrieve data from an OBD II vehicle
Read and display all available I/M Monitors (emissions)

Is this the information I need to know to diagnose my problems?
Thanks!!
Arden