PO132 and PO172 codes keep appearing after about three weeks of trying to get rid of them. Have installed a new gas cap two Bosch 02 sensors one Denzo O2 sensor. What next? Install a Delco O2 sensor?

Has new reman feel injectors and runs good. A very fast idle finally went away yesterday after using seafoam about two weeks ago in the throttlebody and intake.

i'm at a loss, and would like to get on with other pursuits in life. Thanks for any input.

 

P0132 SATURN - HO2S Circuit High Voltage Bank 1 Sensor 1

P0172 SATURN - Fuel Trim System Rich Bank 1


P0132
Bank 1 Sensor 1 is the pre-cat 02 sensor. I believe the heated circuit high V implies it is "shorted to v" or the output signal is sitting at a high v not normal for the device.
This can be due to sensor failure but can also be due to damaged wiring or a damaged connector that attaches to the sensor.

1) What does the FRONT O2 Sensor output look like on a scan tool (real-time data) or even just monitoring the V?

Use Denso O2s in S cars.
My s cars and many others puke on Bosch O2s.
AC Delco are Densos in an AC Delco box that you pay extra for to get the AC Delco box. They are usually not even labeled AC Delco b c that costs 0,09c per sensor.

RockAuto.com indicates which denso is the actual OEM sensor.

Measurement /behavior of the front O2 needs to be determined in order to determine whether the issue is the sensor, the wiring, or something less common.
If you see the same behavior with a new denso front O2, the issue is likely in the wiring -- but let's not get ahead of ourselves

P0172 Rich code
Likely directly related to the goofy output the front O2 is sending to the PCM. The PCM is trying to lean out the air fuel mixture based on the fron O2 reading it is seeing, but it is at the limit is able to do so and still thinks the mixture needs to be more lean.
This seems consistent with the front O2 saying there is a ton too much O2 being created-->mixture too rich---can't lean it out enough --->P0172 set.

So solving the O2 situation should take care of the P0172 at the same time.

I assume these codes appeared together?

Have you done any work near the exhaust manifold/Condensor/radiator? Might have injured wiring?

 

Thank you very much for your helpful reply! I was in the process of shopping for injectors when I read your comments. Yes both codes are presently active. I will check the wiring but there is no glaring wire damage.

I read the voltage on one of the Bosch O2 sensors when hot, and it was 1.8V. I was told by an AutoZone employee that the nominal is around .4V

I will read the voltage on this Denso O2 sensor.

 

!.8V is crazy high -- hence the code.
Many wiring issues are quite hidden; breaks, crosses where two wires have chafed against each other and the insulation has worn off both, allowing them to touch.

the voltage is actually fluctuating between .7 and ,2 ish V during normal operation. Your multimeter may or may not be able to keep up with it but it should not be pinned at anything and certainly not that high

I don't know what the V is that heats the O2 sensor (or if the front is even heated ? 4 wires heated, 2 wires unheated.

Do not throw parts at it -- expensive guessing game and adds more variables.

 

Inclined to think that the problem is not wiring. Today I followed the single wire that goes from the O2 sensor to the PCM. I at first suspicioned that acid from the battery had Affected the harness that goes under it. I pulled out the battery and it's Tray and looked over the harness finding no damage, and found certain continuity from the single 02 sensor wire to the computer's multi-wire plug And saw no other cross-continuities on various pins.

I suspect that the low priced reman injectors that I bought when I couldn't find any that were definitely American made and that weren't extremely expensive.May be leaking. When I first start the car, it 4-cycles for a little while, seeming to indicate that the injectior(s) leaked previous to starting.

My wrecked '02 SL1 had new (not reman) injectors installed not too many months before the car was totaled. That car has sat only a little less than three months, so I'm figuring those injectors are good and need to be transferred to this '01 car, with new seals of course. Thanks again for your helpful ideas!

 

In your original post, you did not indicate the time relationship between when you installed the reman injectors and when the codes first appeared.

What was the timing on that?

What was the timing on the high idle versus appearance of codes?

What was the motivation for replacing the injectors? What is the fuel pressure key on engine off and key on engine on?

Are you using antiseize on the sensor threads?
The measurement is made as a comparison between the oxygen content in the exhaust stream versus the ambient oxygen ie the oxygen concentration in the vicinity of the body of the sensor. If you use an anti-seize compound on the threads and get any of it further up on the sensor, you risk covering a small hole that is present and is used to sample the oxygen concentration near the sensor body. The result is that the measurement goes to hell.

I am not saying that the problem is not the injectors. I'm simply asking for clarification on the original information to ensure I'm not on the wrong trail.

 

I believe it gave a PO172 code alone at first. I remembered that being the case on my '02 also, and installing NEW injectors fixed it. I hunted online for quite a while before I found that last set of NEW injectors that one vendor was selling.

I knew the '01 being low mileage (about 69K) likely meant that it sat a lot in south TX which made me wonder if the gas had soured and fouled the injectors. I had not experienced a delay in the fuel coming up to running pressure on the '02, but that was The case on the '01 right after I bought it, and on a previous Saturn, I had solved that problem by changing out the fuel pump, which I was quick to do for this "01 because I don't want to get stranded on the highway like I did once with a '97

When I installed the remans in the '01, the code never went away and was joined by the PO 132, which led to 3 - O2 sensor change outs. I used minimal anti-sieze, applying it out at the start of the threads.

The fast idle has appeared since the remans were installed. My next step to fix it is to pull the throttlebody section from the intake on the '02 and put it on the '01 with a new gasket. I suspect the idle control, but I will get what was a good operating pair, along with the TPS, from the '02.

Sadly the delay in pressuring up to run pressure persisted with the new fuel pump assembly, a Delphi unit.

I will check the fuel pressure as you indicated, by your question about it.

 

Fuel filter changed?

 

I'm confused about the fast idle. You indicated in your original post that it had gone away. Has it returned?

What RPM are we talking about? 1000? 1400 2000?

It would take a lot of crud for the throttle plate to hang up that badly plus you stated that you cleaned it. Those kinds of high idles are usually associated with vacuum leaks. Depending on what all you are working on at the time, it's possible that you knocked vacuum line loose or, due to the heat, the rubber is dry rotted and merely stressing it was enough to tear a hole..

I would try spraying carb cleaner or similar around the entire intake manifold ( don't miss the bottom) and the throttle body gasket. If a visual inspection under the hood does not review anything, possibly do a very very light spray since conceivably whatever you are using is flammable. Some people use water and spray bottle under the hood as anything that can sucked in that is not air will change the idle indicating a leak

With the PCM trying to lean out the mixture, the pulse width for the injectors would be getting smaller and smaller to lean out the mixture. I am wondering if your fuel pressure regulator which on third gen s cars is part of the fuel filter, is malfunctioning and actually the fuel pressure is too high. That is the one constant in all of this that has not been changed.

We will know when you report back with the fuel pressure.

 

Is this an SL1 or an SL2? I do believe SL1 s had an issue with the intake manifold gasket getting partly sucked in due to a poor design. I can't remember if it is around number one or number four but if you search on intake manifold you should find a bunch of posts stating the range of years that the SL1 intake manifold was an issue.