Oldsmobile/Buick Repair/p1133

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QUESTION: Hi Tom,
99 Buick Park Ave 3.8L plain jane
I'm stumped on this. Keep getting p1133, even after I replaced the Ho2 sensors, MAF, checked intake for leaks(sprayed carb cleaner all around while running, no idle change), fixed plastic air lines coming from intake split Y to FPR and Vacuum solenoid, installed fuel injection additive, replaced EGR valve gasket, replaced fuel lines front to back, new fuel filter... I checked the fuel pressure last week, said IIRC 45 KOEO, 39 KOER, 50 or 54 with running and FPR vac line unhooked, no leakage in line. Don't hold these numbers exact, as I forgot exactly what it was and can redo it no problem anyway. I just remember the results looked good to me. I use the Actron cp9135 autoscanner, but really it's just a code reader. I've been throwing parts at it with no results. I may have to visit my friend who has the Snapon new MT whatever and reads everything. But first Tom, am I missing something here? Thanks again for your help.

ANSWER: HI MIKE, WELL YOU DID ALL THE CORRECT THINGS AND MORE THEN LIKELY REPLACED TO MANY THINGS...LETS START FROM SCRATCH...HAVE YOU CHECKED ALL OF THE WIRING HARNESS TO THIS B1 S1 ?? I HAVE FOUND MANY BROKEN WIRES LEADING TO THE PIGTAIL OF THE SENSOR ITSELF.. BUT WITHOUT LOOKING THIS UP AT MY SHOPS COMPUTER AND SPENDING TIME TO CK THE FLOW CHARTS ON THIS I WOULD GRAB YOURSELF A VOLT METER, START YOUR CAR AND PULL THE HARNESS OFF THE O2 B2 S2 MAKE SURE ENGINE IS HOT AND NOW CK ALL THE VOLTAGES TO THE GOOD SIDE O2 SENSOR.[[YOUR CHECKING THE HARNESS FROM THE COMPUTER NOT THE O2 SENSOR.]] NOW MATCH THESE READINGS UP TO THE B1 S1 SEE IF THEY ARE THE SAME.[[THEY SHOULD BE VERY VERY CLOSE TO ONE ANOTHER]] I BET YOU WILL FIND THEY ARE NOT..IF I WERE TO GUESS THIS SOUNDS LIKE OPEN WIRE TO THIS SENSOR. IF THIS IS THE CASE START TRACING WIRES BACK TO THE PCM..I THINK YOU CHECKED ALL OTHER POSSIBLE PROBLEMS..LAST THING JUST TO BE SURE, SOME OF THESE YEARS HAD A FUSE FOR THE O2 SENSORS,,CK THAT AS WELL....GET BACK TO ME ON WHAT YOU FIND AND GOOD LUCK TO YOU,,,TOM....

---------- FOLLOW-UP ----------

QUESTION: Great advice Tom. Just to update some, last night I tinkered a bit and tied up some loose ends, things are arising faster than I can take care of them. I was intrigued with what I had heard about Seafoam and decided to try it because this car has always had a prone to be gummed up throttle plate that I've had to tend to numerous times and recently it was acting up showing itself by that first push of the accelerator, which would click like it was slightly stuck. So I gave it a shot. Put 1/3 can in tank, 1/3 in crankcase and the last 3rd through the brake booster vacuum line to intake while running. As far as I can tell, it didn't do anything bad. No smoke like I've seen others do and it almost seems as if it runs a little smoother because of it. Don't like the idea of a gas like cleaner in the crancase as I think it would thin the oil and not be good in long run for top end oil protection. So I want to change that oil in a week or so. Regardless though, it has nothing to do with the p1133, just wanted to try that. I'd like to know your opinion on that stuff, as I've always known there has never been a quick fix in a can, but for 7 bucks and some people swearing by it, I gave it a try.

I didn't get to check the voltage variance yet between the front and back ho2 sensors and I'll tell you why. I spent some time looking over the wiring, but still have to cut the plastic off of that very major part of the harness and check it visibly. It looks good, but that means nothing as you know. Today I took a ride over to my buddy's garage and he hooked it up to his very new awesome looking Snap on scanner. It provided live stream data for everything, graphs and so forth. I had been waiting to cycle it a few times and get the IM monitors ready for inspection, but was foiled a few times because the CEL came on either just before I got there or it wasn't ready. I was close today, as it was cycled twice, no CEL on, but only had 5 monitors ready while 3 were not and although the code was still showing on my Actron, it didn't illuminate the CEL. The 3 were Ho2Sensor, Evap and catalyst. The battery had died while it was hooked up KOEO (battery is spotty and charges iffy, but new one isn't in until next week, so stuck with it a few days). So, it reset everything by the jump and once again not ready for inspection. But I saw graphs of everything and most importantly the front and rear O2 sensors, which were BOTH right in the limits they needed to be and switching perfectly. So I'm atleast getting very narrowed down here and I think it points me to either 1) pink heated wire for sensor going back to PCM has an open or 2) new sensor isn't heating up. But I've tried 2 different new sensors, one AC Delco in right now, the other Bosch on bench. I think my next step is to open up that huge wire loom going from o2 sensor to the driver side wall. It looks intimidating, but that's my plan for tonight, to inspect that. On a side note, I guess a last option could be 3) sensor is not a heated O2 sensor. Not sure how often that happens, but I suppose they look the same. Mine has a 4 wire square plug. I ordered them online and inserted the parameters myself. Not sure that is a likelyhood, but worth mentioning anyway. Thinking best bet is to visually inspect wires and get that possibility out of the way. It's a process, but I'm getting there I think.

If you have any other input, as to what I reported about the scanned results today, please let me know. I will keep you abreast of any new developments I get. Thanks.

ANSWER: HI MIKE, THANKS FOR GETTING BACK TO ME ON THIS..TO SAVE YOU A LOT OF TIME ON OPENING UP THE HARNESS. TEST EACH HARNESS AS I SAID ABOVE AND MATCH THEM UP TO SEE WHAT KIND OF VOLTAGE YOU ARE GETTING..THIS MAY SAVE YOU SOME TIME.. THEN  IF YOU SEE A LOW OR NO VOLTAGE SIGNAL GO AFTER THAT.
BUT LETS SAY YOU ARE LOOSING THE 5 VOLT REFERENCE FROM THE PCM,RUN A WIRE FROM THE SIDE THAT YOU ARE GETTING A SIGNAL FROM..THIS WILL TRICK THE PCM OUT..WHY LOOK FOR A PROBLEM THAT [MAY NOT BE THERE] JUST SAYING...AS FAR A SEA FOAM GOES I HAVE HEARD GOOD THINGS ABOUT IT,BUT I HAVE NEVER TRIED IT MYSELF..BUT MANY PEOPLE SWEAR BY IT...GET A NEW BATTERY TO,PLAY IT SAFE...LET ME KNOW HOW THIS GOES..GOOD LUCK TOM..

---------- FOLLOW-UP ----------

QUESTION: Tom, I rechecked the wiring harness visually back to the PCM. Looks good. Checked harness pink wire to Ho2 sensor KOEO, got 11.54 volts. Put in known new battery, car kept not starting once it got colder. Drove to garage and CEL illuminated just a mile from there. Rescanned, got codes p171 twice and p1133 again. Visually inspected underhood area again, found vac hosing from intake to FPR to Evap sol was broken. I will assume the p171(bank 1 lean) was from the broke hose and repair that as necessary.

As for the p1133, I'm sure that will come back, as it has every time now. I was mistaken on one of the 3 not ready monitors, it was actually the O2 sensor not ready, not the HO2 sensor as I originally stated. Once the 6th monitor became ready, I immediately hooked up and saw it was the O2 sensor monitor becoming ready that triggers the CEL. Why, I still don't know. This is a brand new sensor(and also tried another new one, Bosch, both same result), wiring appears ok, nothing obvious, so I need to ask for 2 things... 1) Could it be a bad pigtail on the harness side, not sensor side? Maybe I should splice another one in from a junkyard to check. and 2) I checked the harness KOEO and said above I had gotten 11.54 volts to sensor, How do I check the other 3 wires in that plug? I suppose there's a ground and heater wire and ? That's where I'm at right now. Garage has looked with new Snapon scanner, according to graphs, O2 sensors are switching fine. There was a list of things to check, but I've already all but verified them, no exhaust leak, good fuel pressure, 1/2 tank of gas or more, sprayed whole top of engine KOER- no idle change at all, new MAF, could an IAC be an issue for this code? That p1133 air and fuel metering will bother me until I get it. Thanks.

Answer
HI MIKE, WHEN THE MASS AIR FLOW FAILS THIS WILL 99% OF THE TIME SET BOTH O2 SENSORS INTO OUTER LIMITS, SETTING BOTH BANK SENSORS CODES. AS FAR AS THE SIGNAL TO THE O2 SENSOR ONE WIRE IS BATTERY VOLTAGE,THE OTHER IS SIGNAL FROM THE COMPUTER 5 VOLT REFERENCE,GROUND AND AGAIN A SIGNAL FROM THE PCM TO TURN ON THE HEATED SENSOR ON...BUT AFTER ALL OF THIS DID YOU CK THE FRONT AND REAR or bank 1 and 2 BANK SENSOR WIRING HARNESS FROM THE PCM [THE CAR SIDE HARNESS NOT THE SENSOR SIDE AND COMPARE VOLTAGES,,WITH THE CAR RUNNING ?? ?? SO YOU KNOW FOR SURE THEY WERE ALL THE SAME..WHICH I AM SURE THEY CAN NOT BE. SO COMPARE THE GOOD BANK SENSOR WITH THE FAULTY ONE.I WANT YOU TO CK ALL FOUR WIRES ON EACH SENSOR TO A-B THEM RIGHT DOWN THE VOLTAGE OF EACH ONE TO COMPARE..MAKE SURE THE ENGINE IS RUNNING AND HOT ..IF YOU DID THIS I MUST OF MISSED THIS IN YOUR QUESTION. YES IT IS POSSIBLE THAT THE PIG TAIL COULD BE BAD BUT LETS CK FRONT AND REAR TO A-B THEM. LET ME KNOW ,,TOM....

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TOM SHEETS

Expertise

Can answer all questions pertaining to mechanics of GM cars from 1965 to present. I will answer questions from 6:00 am to 10 pm est.. I will not take diesel or paint questions. If this olds and buick section is maxed out you can get to me in the chevrolet section...

Experience

I have 30 plus years experience in servicing these cars. I can answer questions on carburetor, fuel injection,ignition systems, suspension, brakes and abs, cooling systems,a/c and heater,manual transmissions, rear differential and electrical system,charing system and battery. I am a Master ASE certified mechanic in all 8 categories: - Brakes - Heating and Air Conditioning - Automatic transmission - Clutches and Transaxle - Engine performance - Engine repair - Electrical - Steering and suspension I am certified for NYS inspection and clean air insp.

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I am a Master ASE certified mechanic in all 8 categories (see above) I am an Air Conditioning/Freon recycling specialist with ASE. I have at least 4 years of technical training and many hours of continuing education.

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many customers in our busy shop for the past 30 plus years

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