Buick Repair Questions? Ask a Mechanic for Answers ASAP
Hello, my name is ***** ***** I will be glad to assist. Please allow me a moment to gather some information.
ok, can you tell me what the long term trims are when idling???
Circuit DescriptionThe PCM monitors the Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this test period the PCM counts the number of times that the HO2S signal voltage crosses the rich to lean and lean to rich thresholds. If the PCM determines that the HO2S did not switch enough times, DTC P1133 will be set. A lean to rich switch is determined when the HO2S voltage changes from less than 300 mV to greater than 600 mV. A rich to lean switch is determined when the HO2S voltage changes from more than 600 mV to less than 300 mV.Conditions for Running the DTC
are you there
ok, engine warm and will read in percentage.
1.6 is good but 10.9 means it is running lean
check the pcv valve to be sure it is not stuck open
check for vacuum leaks
check the fuel pressure as well. low pressure will make it run lean
please dont forget to rate me as it is the only way I get paid for my efforts
I did not see one of my responses posted. it is about your fuel pressure. it is under spec. low fuel pressure will cause this lean condition. the spec is below for you to view
1999 Buick Regal V6-3.8L VIN K
Vehicle » Specifications » Pressure, Vacuum and Temperature Specifications » Fuel Pressure
Key On Engine Off48-55 psi
replace the fuel pump is the solution
I have read all your responses.
no where do I see any pressure within the specs that are required. I am missing nothing here at all.
46-52 lbs key on engine running
no, the pump is not building enough pressure. the pump needs to be replaced to get the pressure up to spec. then the sufficient amount of fuel will get into the cylinders and the O2 sensor will start working again.
with the new pump and pcv, what are the long term trims reading now???
yes, it is running lean
I agree. it is always 3 days waiting for a response from you anyway.
you also never stated if you replaced the pcv as it will effect long term trims
New expert here, I can send you the repair procedures for this code from the factory service manual if you would like.
Yes, it will allow me to email you the info you need.
Check the intake gaskets on the manifold this is a common problem. Also replace the fuel filter.
Also this could be a mass air flow sensor problem. I would try to clean the MAF first then replace it.
Look at the voltage from the front O2 sensor
Look at the freeze frame data as well.
Keep driving it until you get a code, then show me the freeze frame data. Is it running any better than before?
Hello again Dan here,
I am contacting you because the post has not been closed or rated.
This question is coming up on 7 days which means it will time out and close.
You have already paid to get this question answered, but you have not rated.
Let me help some more. Is there anything else I can help you with?
If I did not give you 5 star service, please let me know what I missed.
DTC P1133: HO2S INSUFFICIENT SWITCHING SENSOR 1 (3.8L "C", "G", "H" & "W" BODIES)
NOTE: For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.
PCM monitors Heated Oxygen Sensor (HO2S) activity for 100 seconds. PCM determines if HO2S 1 is functioning properly by counting number of HO2S 1 Lean/Rich (L/R) and Rich/Lean (R/L) switches. If PCM determines that HO2S 1 did not switch enough times, DTC 1133 is set.
Conditions for setting DTC are: PCM monitors fewer than 40 lean-to-rich and rich-to-lean switches for bank 1, sensor 1 HO2S, HO2S voltage remains between 300-600 mV and conditions are present for 2 minutes after "closed-loop" enable.
Check HO2S 1 heater operation. If HO2S 1 heater operation is okay, replace HO2S 1.
Need to go through all 11 steps in order to diagnose.