Hey so I’ve never done this before but I have an 06 Silverado has the 5.3 in her. So here’s the thing. The last couple weeks she’s been throwing codes at me first the MAF sensor so I replaced it then the air filter so I replaced it. Then it went to P0172 and P0332. Then it went to P0172, P0327, P0332. Well it said clean TPS. So that was replaced. It went back to the P0172 stayed like that a couple days except the check engine like started flashing. Well I started it today and now I got P0172, P0327, P0332, and first time ever P0128. Is this like a computer thing or does one thing after another really happen like this. Also it recently started going into limp mode but good news is it don’t backfire anymore 😩 help

 

Welcome to the Forum!

Sorry you are having engine problems but I'll see if I can help you figure out what is going on.

First, why did you change the MAF sensor? What was the original code that made you think it needed changing?

Second, Diagnostic Test Codes (DTCs) NEVER EVER tell you that a given part is bad, broken or defective. Remember this!

Third, DTCs tell you that there is a problem with a given circuit or system, and it provides you with a point to start diagnosing why that particular code was set. Many times the cause of a DTC is a bad ground connection, a loose wire, a broken wire, an unplugged connector, a dirty connector, a defective part, etc. In other words, do not automatically assume that it is the part's fault.

OK, so now for the 4 DTCs your OBDII system is reporting. P0172 is telling you that bank 1 of your engine (the driver's side of the engine) is running rich. P0332 is telling you that the Knock Sensor 2 electrical circuit output is lower than expected. P0327 is telling you that the Knock Sensor 1 electrical circuit output is lower than expected. And finally, P0128 is telling you that the engine coolant temperature is below an expected temperature and therefore the engine's thermostat is not able to regulate the temperature of the coolant.

Now, when multiple codes show up at the same time, experience tells us that there is likely a problem that is common to all 4 codes. In this case, I suspect that there is either a bad ground connection, a multiwire connector has come undone, or there is one or more broken wires. With respect to the broken wires, I would look the wiring on the driver's side over to see if any critters have been feasting on the wires and have chewed through the insulation and possibly the wires. Mice love to chew on automotive wiring insulation since the insulation is derived from soybeans.

Now in order to further assist you, you will need access to diagrams that show grounding points, electrical schematics, troubleshooting charts, etc. There is an online source for free service manuals at https://charm.li/, All you need to do is to click on Chevrolet, then click on the vehicle year, and then the model of your Silverado. Out of all the vehicles listed, choose the one that is closest to yours (e.g. 5.3 l engine, 2 wheel drive, 4 wheel drive, etc.)

Good Luck!

 

I originally changed the MAF because the truck was not running great and when I unplugged the sensor it ran way better so I assumed that wld help. Which it has. Truck stopped backfiring doesn’t idle as high and chaotic less gas usage ect. However now that is fixed I’m getting a code for the throttle both knock sensors and the bank 1 to rich. Live data from what I was told and understand does not look awful my IAT runs a little low and my spark advance averages at 18°. I don’t know a whole lot about this truck I’ve had it less then a year and never really gave me issues. When I first bought it I had the tps changed on it because the guy I got it from said that was why my chk engine light was on. A few months later it started getting low gas mileage backfiring and so on. But it’s not all the time. Just sometime. Other times the truck runs fine. It does have a bit of an evap smell now which is new so I’m gonna have that checked in to I don’t have issues with gas or anything other then sometimes it’s eats it. When it’s in a mood It takes me almost half tank of gas to drive 23 miles to work. But when she is running fine I get about 14 mpg. I thought it was a fuel injector issue because it cuts out and goes in limp mode and looses acceleration can’t go over 40 but those was tested and apparently fine. So I guess I’m having the wiring looked at next. I have put 2 starters on it since march they had to replace that wire so maybe hopefully it’s just another one.

 

LenaMarie - Please go back and re-read what I posted very carefully. My first thought is you have a loose and/or broken wire or two that are causing the various problems.

If the PCM cannot get the correct information, from the sensors, then the engine will run rough.

OK on the MAF sensor and why you replaced it, and that the previous owner told you to replace the IAT valve.

DO NOT spend any more money on parts until you have diagnosed what the problems are. If the cause of the problems is a broken wire, replacing old parts with new will not correct anything, and you will have thrown away your hard earned money for no good reason.

Think logically. Go from A to B then C followed by D. DO NOT go from A to W to M to Z to B, then over to Q and R...

 

I had the same issue with my dads 06 4.3. It was the wire harness, had 4 bare wires touching and causing havoc. I fixed the wires and fixed the tps sensor that shorted out.

 

https://chevroletforum.com/forum/199...-115284/page2/