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Need help interpreting these. Codes are cul 5 misfire and banks 1 n 2 o2 sensor bad
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What are your exact codes?
How does it run? Does that change if it goes into closed loop? Those are some funky fuel trims, something definitely going on. We need them at idle and 2500 rpm all in park warm engine Need all those same sensors on a cold engine at key on. Need to see those O2 sensors graphed like this: https://cimg2.ibsrv.net/gimg/blazerf...b4e3744e9d.png https://cimg0.ibsrv.net/gimg/blazerf...cc58d95a81.png George |
Mey
Originally Posted by GeorgeLG
(Post 745114)
What are your exact codes?
How does it run? Does that change if it goes into closed loop? Those are some funky fuel trims, something definitely going on. We need them at idle and 2500 rpm all in park warm engine Need all those same sensors on a cold engine at key on. Need to see those O2 sensors graphed like this: https://cimg2.ibsrv.net/gimg/blazerf...b4e3744e9d.png https://cimg0.ibsrv.net/gimg/blazerf...cc58d95a81.png George https://cimg0.ibsrv.net/gimg/blazerf...25a5251926.png
Spoiler
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Thanks, I’ll look at this later today
George |
We need three sets of data all taken at the same time:
engine cold, key on engine off idle warm in park 2500 rpm warm in park. Also can you graph the O2 sensors like in post 3? Lastly we need the MAF sensor at the full throttle shift point on a warm engine. Can you read CMP retard? We should look at your #5 plug and at least one next to it after you verify that CMP retard is in spec Some discussion: Your software has report insufficient O2 sensor counts which means that they may not be switching or not switching soon enough (heaters) hence the graphs. You get an improper MAF reading at 0 RPM so we need to see it at idle and the shift point We need CMP retard before we get too carried away focusing on cylinder 5 since that affects the accuracy of the reported misfires. You have O2 sensor heater codes which means that they will be slow to warm up affecting emissions and fuel economy to a small degree. They may also not be starting fast enough to satisfy the computer. This is usually no problem at speed but at idle the sensors can get cold enough to stop working correctly, and again be slow to start. This can be the heaters in the sensors or the power and ground or wiring to the sensors. We need to fix this eventually. We can either test the circuit or you can swap with a known good O2 sensor to see if the heater code persists. If your not up for all this data then pull the #5 plug and at least one more and lets get your O2 sensor heaters fixed. George |
Originally Posted by GeorgeLG
(Post 745140)
We need three sets of data all taken at the same time:
engine cold, key on engine off idle warm in park 2500 rpm warm in park. Also can you graph the O2 sensors like in post 3? Lastly we need the MAF sensor at the full throttle shift point on a warm engine. Can you read CMP retard? We should look at your #5 plug and at least one next to it after you verify that CMP retard is in spec Some discussion: Your software has report insufficient O2 sensor counts which means that they may not be switching or not switching soon enough (heaters) hence the graphs. You get an improper MAF reading at 0 RPM so we need to see it at idle and the shift point We need CMP retard before we get too carried away focusing on cylinder 5 since that affects the accuracy of the reported misfires. You have O2 sensor heater codes which means that they will be slow to warm up affecting emissions and fuel economy to a small degree. They may also not be starting fast enough to satisfy the computer. This is usually no problem at speed but at idle the sensors can get cold enough to stop working correctly, and again be slow to start. This can be the heaters in the sensors or the power and ground or wiring to the sensors. We need to fix this eventually. We can either test the circuit or you can swap with a known good O2 sensor to see if the heater code persists. If your not up for all this data then pull the #5 plug and at least one more and lets get your O2 sensor heaters fixed. George Also, I won't be able to provide the report as far as idling diagnosis and 2500 rpm diagnosis. My old man pulled the 02 sensor out and looking into it. So as soon as I have it reinstalled or new one put in. I'll be able to provide the info. Man I sure appreciate this. It has been one heck of a year dealing with this Blazer and it's been a constant something here something there and this little last bout with this misfire and fuel injector I'm about ready to start pulling wires and stuff from underneath the hood that's about how sick of this truck I am. But anyways thank you so much for helping me and I am going to get back with you as soon as I had the sensor put back in |
George can definitely help you, but keep in mind that you may need different OBD2 scanning software. Seems like what you are using is inferior. Good luck! What is it that you are using?
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Les knows scanning software better than anybody so he can help you get better capability.
As far as me, I'll stick with you as far as you want to go. We can definitely get your truck fixed but like Les says, you may need better "tools" Also, an O2 sensor circuit code does not necessarily mean a bad O2 sensor, George |
Originally Posted by GeorgeLG
(Post 745151)
Les knows scanning software better than anybody so he can help you get better capability.
As far as me, I'll stick with you as far as you want to go. We can definitely get your truck fixed but like Les says, you may need better "tools" Also, an O2 sensor circuit code does not necessarily mean a bad O2 sensor, George |
I will do my best to help you and work with your situation. I understand cancer all too well.
Lets slow down then and get our bearings. Are we trying to fix this truck or just trying to figure out what's wrong with it so someone else can fix it? Did these problems start after a repair, or any other event? What is the software that you are currently using to show us this data? Do you have an Android device (phone or tablet)? Do you have and know how to use a digital multimeter? Do you have a test light? Here is what I can tell you for now. Your O2 sensor codes are for the heater circuits in the sensors which warm them up faster to get to lower emissions and better fuel economy faster. They also make sure that the sensors dont cool off too much and drop out under certain operating conditions. Most of the time the truck runs OK even with this fault. Anytime you get a sensor code it may be the sensor or it may be the rest of the circuit (connectors, wiring, power, ground, engine computer). You determine that with testing which we can do. This prevents the parts cannon and unnecessary replacements. The cylinder 5 misfire can be many things and again we determine that with testing. I asked about the ability to read CMP retard because that parameter must be adjusted to within spec or the misfire cylinder that is identified may be wrong. I'll know more when you tell me about this code reader. If there is a misfire and if its only on one cylinder it can be a few things: Poor ignition (Distr/wire/plug) Faulty fuel injector Poor cylinder compression (bad valve/piston/head gasket) Bearing knock etc Once we get CMP retard within spec and confirm cylinder 5 an inexpensive thing to do is swap ignition wires and see if it follows, inspect the distr cap, look at the plug and mist the engine with water in the dark at idle and look for arcing. I'll stick with you as long as you want my help and I'll look for ways to do this on the cheap. Besides understanding cancer I was also a broke ass college student once with a money pit first car (ask me how I learned all this stuff). I traveled with all of my tools and meters in the trunk. lol George |
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