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Discussion Starter · #1 ·
So, I replace the O2 sensor on my '97 2.3 N/A because of a CEL light and code 133. Drove for 30 miles and the CEL comes back, but with no code. This code has come and been reset 5 times in the past year and always read no code. Autozone got a 133 with their scanner, so I just replaced it. I have the same situation as before the O2 sensor replacement. Bank 1 (upstream of the catalytic converter. Any suggestions or advice?
 

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So, I replace the O2 sensor on my '97 2.3 N/A because of a CEL light and code 133. Drove for 30 miles and the CEL comes back, but with no code. This code has come and been reset 5 times in the past year and always read no code. Autozone got a 133 with their scanner, so I just replaced it. I have the same situation as before the O2 sensor replacement. Bank 1 (upstream of the catalytic converter. Any suggestions or advice?
Yeah - don't go to AutoZone for free code pulling - doesn't work on Saab's.... you get a bogus code like that and end up replacing the wrong part - AutoZone wins.

You need to invest in a decent code reader or find someone with one and get the proper code pulled - until then you can just keep guessing and tossing money at it. Sorry to sound prickish - but this is what I was just talking about in another thread - it hurts the consumer.

There are 2 O2 sensors in your car - they may both be working 100% telling you there is a fuel mixture problem - aka, lean or rich mixture. There could be a vac leak somewhere or worse case the Catalyst could be bad. You need the code pulled right - then let us know and we can help.

Some code readers were mentioned in this thread;
http://www.saablink.net/forum/showthread.php?t=51163
 

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Discussion Starter · #3 ·
Thanks

OK, thanks Burnside. My old (15 yrs) Actron code reader comes up blank, that's why I went to AZone. Sensor was $70, old one was pretty "carboned up". I kept the old one, it'll be a good spare. The condition that seems to be setting the code is somewhat lugging the engine, the engine just pulls so well from a low rPM, like a diesel. I have a friend with a Tech II, just have to travel a little.
 

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OBD II codes are standardized, and unless your car's throwing a Saab-specific code, the reader at Autozone will read it just fine. P0133 is a slow response from the front O2 sensor, but if you Google that code, you'll see that it can be more than the front O2 sensor.
 

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Discussion Starter · #5 ·
Thanks Jeremy,
I thought that might be the issue after Burnside's advice. I'm getting a saabtech to check it in a few hours. Now I feel like crap for advising Saab owners to go to AZone for free code reading. It's really not free when they tell you that you need something you really don't need. I thought the slow O2 response might be related to the lugging issue, but yesterday the CEL came back at highway speeds. Anyway, thanks again
 

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Discussion Starter · #6 ·
Update

Pulled code 1115 with a better scanner used by an indy and replaced the temperature sensor for the ECM. CEL came back 30 miles later as I was doing the OBDII drive cycle.
Any other suggestions out there?
 

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Pulled code 1115 with a better scanner used by an indy and replaced the temperature sensor for the ECM. CEL came back 30 miles later as I was doing the OBDII drive cycle.
Any other suggestions out there?
Just as prevent. maint. you should change the thermostat with the sensor typically - but it seems that the P1115 code is "Front Heated Oxygen Sensor Bank 1, Control Module Input, Current in Pre-Heating Circuit Too Low"

Is there a fuse? Is it good? You replaced the sensor with a new one you mentioned - was it an entire harness or a splice job?
 

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Discussion Starter · #8 ·
CEL Update

Well, it took about 30 miles to get the CEL again. I went to the next level of wizardry on this car. He fought the same problem in the same way as I did with the same results. He can't explain why, but he said simply resetting the code did not solve his similar problem. He said I needed to remove the negative cable from the battery and hold it against the positive terminal for about 10 seconds.
Doing this will totally discharge anything left in the ECU and totally reset the logic. So far it's worked. No CEL. Gonna run the wheels off it this weekend. He said it's an old trick on the Motronic 4.1. Been doing the OBDII drive cycle thing. We'll see.
 

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Now I feel like crap for advising Saab owners to go to AZone for free code reading. It's really not free when they tell you that you need something you really don't need.
If it's a generic OBD-II code, then autozone or whatever is fine. The key is to get the code from them and ignore what they say about the code meaning you need to replace X Y or Z. The code indicates a symptom, and Saab has a list of things to check (see WIS) that could cause that symptom. When you get a P0133, it could be the O2 sensor but it could also be a wiring problem. Autozone just wants to to buy an O2 sensor. You should write down the code they give you, then use WIS or google or saablink to do further diagnosis.
 

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Discussion Starter · #11 ·
Update

So, I go to a saab dealership, P1115 is "preheating current <600 mA after 150 seconds". Check fuse 38 (good), then check resistance and preheater circuit availability. Pretty simple and will do tomorrow.
 

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Discussion Starter · #12 ·
Update #2

The Bosch "universal" 02 sensor that I installed because of the P1115 code produced the same symptom as the original stock one. The obvious assumption was that the 02 sensor was not the problem.
WRONG!
The heater circuit resistance for the new 02 was 8 ohms and that was out of spec enough to eventually throw the P1115 code when the circuit went to less than 600 milliamps. I put in a good used 02 sensor, reset the code, and have driven 200 miles with no return of the CEL. I had changed the Motronic 4.1 ECU thinking that the ECU was misreading the current. Got a spare ECU now to go with my 100 other spare NG900 parts.
BTW, Autozone was right about the 02 sensor, Advanced Auto Parts sold me the 02 that won't work.
 
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