Installing SRI Gold kit today - little help?

Ok, I am assuming the O2 sensor on the OBD II cars is a 4 wire. Since you changed the terminals you should know if it's 3 or 4 wire. Assuming 4 wire, there should it should be either type 1, 2 or 3. Type 1 has two black wires, a whire and a blue. The heater is connected to the two black wire. Measure the resistance between the two black wires. Type 2 has 2 white, a gray and a black wires. Measure the resistance between the two white wires. Type 3 has two black, a red and a white. Measure the resistance between the red and one of the black wires. If you get a very high reistance or open circuit, measure the resistance again between the red and the other black wire.

Just want to add that the resistance is measured with the O2 sensor disconnected from the ECU.

 

Your multimeter should have a setting for measuring resistance (ohms) and two lead wires. Set the multimeter to Ohms. If yo can set the range set it for x.xx range as you are measuring a resistance that should be on the order of 2 to 7 ohms. Turn on the multimeter. Connect one lead to one white wire and the other lead to the other white wire. The meter should display the resistance.

As a test, before you try to measure the heater resistance, just touch the two leads of the meter to each other. You should see the meter display 0.0 or a very small resistance like 0.1 ohms (the resistance of the leads).

However, it seems strange that you are getting heater error for all the O2 sensors. This might indicate the the heater circuit is not working from the ECU which could be a bad fuse. If the resistance of the sensors is ok then you need to see if you are getting power to the sensors. That gets more complicated. Some ECUs make or break the hot side (12v), some make or brake the ground. Some do this when the ignition is switched on, some only activate the heater circuit if the car is started.

 

I would wait until Ketel finishes his pin update before a full diagnosis. If by then, these errors continue to exist then the prognosis is not good for the ECU board. The voltage measurement (as in no 12V applied to the leads) and the current measurement (as in no current flowing through these leads) capabilities are likely inside the ECU and having all O2 sensors go bad (while they are not bad) means that the ECU is bad.

But, let's wait until all the pins are done.

 

If you have not done the ecu...what specific sensors have you done?

Also, are you completely disconnecting the battery before you restart the car each time to pull the codes?

 

Thanks for the info....it will take a bit to read it. It seems that the oxides will cause an increase in resistance... Which I imagine will be most detrimental to the lowest voltage circuits...like the o2 sensors. It also points to higher clamping force being a great thing to stop the fretting....and increase continuity in circuits

 

Switch off the battery at the disconnect switch in the boot.

 

ketel,

here you go:

turn your dial anywhere in the ohm section its the omega sign one. see where pen points

note the probes are not touching which denotes an open circuit. On this DVOM it reads 0.L
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here the probes are touching and dial is the same place. 0.00 denotes no resistance a completed circuit.
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now touch one probe tip to a white wire and the other probe tip to the other white wire and read the DVOM.

Good is any low number like 50 ohms or less. This good 02 sensor reads zero

A bad heater circuit would read "open" or 0.L like the first picture. Think about the exposed heating elements in your toaster oven and what would happen if your oven was on and you cut the curlie que element with a scissors...circuit would be open and no electricity would flow to make the toast hot.
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Just as a question regarding o2 sensors my 99 screws up o2 sensors pretty much every two years. Each time I go to emmisions in Cali, I fail each time I replace the post catalyst sensors and each time it passes easily. Maybe the hyper flows get too hot and reck them I do not know but thought I would share. This has happened for last 10 years roughly. Anybody else know cause. I guess other thing is maybe just replace those two sensors?

 

The short answer is the 355 is brutal on cats because of running rich far to often. Running rich creates more unburnt fuel to be burnt in the cats... creating more heat... killing cats prematurely, trapping more heat in the headers and melting them prematurely and killing O2 sensors prematurely. Why they run rich too often is a whole nother can o' worms.

Some may even point to O2 sensors "dying" prematurely to the 355's ECU being very pick at what it sees from the O2 sensors AND (hint: SRI gold kit) the proper signal the O2 sensors are sending getting to the ECU clearly.

 

Not to start another argument but this should have been done before the gold kit update was even started. If you put a piece of bread in a toaster and it doesn't toast you don't start looking for what is wrong by replacing all the plugs an outlets in you home.

 

No need to remove the sensors from the car. Just unplug the sensor and put your multimeter probes in the connector just so they are touching the contacts. You don't want to stretch those new golds.

Also, have you checked the fuse(s) for the O2 sensors? If the fuses are good and the sensors measure ok then you need to see if you are gettuing voltage to the sensors.

And, on OBD II cars disconnecting the battery should not be required. OBD II will not (should not) reset codes by disconnecting the battery. I doubt that the OBD II on a 355 is any different. Use you scanner to reset the codes.

Here is a link to a Toyota write up on O2 and A/F sensors that may be useful. http://www.autoshop101.com/forms/h37.pdf

 

The last set of O2 sensors I replaced on a 355 was about 3 years ago, and those were the front sensors. Lets just say that sample group involves many dozens of cars.

Blaming the HF's became the thing to do for quite a while, again a matter of searching for a place to lay blame when in reality it had no merit. Steve's statement is well thought out, Cat's only get hot when they are fed an abundance of unburned fuel, a result, not a cause.

""I would wait until Ketel finishes his (FULL) pin update before a full diagnosis""

BINGO. This has already been stated numerous times in this thread, as has the removal of old codes and a proper relearn of the base operating parameters.

 

FWIW, for the 10 or 15 minutes it takes to check the resistance of the heater elements it only makes common sense to check them and PUT THE ISSUE TO BED. If they prove to measure OK then ketel can continue on with the confidence that the heater elements themselves are not the problem.

 

This is what I did. I took apart every connector I could get my grubby hands on. I got this stuff called "De-Ox-It". Spray it into the contacts. It works electrical miracles. Google it. It works. My car runs fantastic. End of story.

 

Deoxit is a miracle worker for restoring electrical connector's performance. I had a box of over a hundred Atari and NES games that had stopped working despite good cleanings. I used deoxit and all but a few came back to life. Remember the flashing screen on your NES, that is why, and blowing on them makes it worse in the long term. While doexit can't magically make weak tin connectors work like quality gold plated ones it could certainly help if the pins were just oxidized (and it doesn't have to be visible oxidation to make a huge impact).

 

Wait... Blowing in the NES games makes it worse?!?!

Who knew?

 

Left turn, here we go again. It's not my fault this time!

 

De-oxit. Yes, I've used it...on my stereo connections. For your Ferrari? Maybe they sell it in suppository form...because I think you'd have better luck shoving it elsewhere.

 

Not following your logic....what does deoxit and Ferrari statement have to do w one another?

This is ALL about continuity in these circuits...Ferrari or a toaster oven. And thanks to Billy for showing how he should test his o2 sensors.

If the continuity problem is from oxidation....and deoxit removes it....then problem solved.

If low clamping force is an issue on a tin terminal...use an upgraded tin connector.

If low clamping force is on a gold terminal...then use upgraded gold connector.

Bottom line is that the goal is continuity w the lowest resistance.....to feed the best signal to the ECU...

..and by the way the same ecu is used in vw, BMW, and Mercedes.....nothing special about the ecu in your Ferrari 348/ 355...except the software running it. And unfortunately, the ecu in the 355 have tin contacts.....the gold ecu was only in the 360.

It's all about continuity....even if its in suppository form.

 

Correct, passing a good quality signal from a weak source to a unit that will process the signal into a finished product with the quality of that result depending on the quality of transfer. Audio gear compared to ECU and sensors is a very good analogy actually.