Code P0203 Hesitation during Acceleration

[Mmorajr69]

I am sorry if this thread has been talked about before but I was not able to find it.
I have a 2011 Camaro SS with 66,000 miles with manual transmission and recently the car started to hesitate when I started out driving in 1st gear and through 2nd once the car got to higher speed it would smooth out.
The Service Stabilitrak warning came on along with the check engine light
and the car threw a P0203 code which is a Fuel Injector malfunction at the 3rd Cylinder.
I replaced the Injector with a same new AC Delco injector and that didnt resolve the issue so I changed the Spark Plugs and Wires with new NGK Wires and Plugs and that didnt change anything, then I cleaned the MAF sensor and that didnt change anything and lastly I checked the injector circuit with a Noid light and it was performing as it should.
Does anyone have any suggestions as to what else it could be or that I can check.

[gtstorey]

Still throwing the code? That is an open circuit code for the #3 injector. I would swap the injector to a different cylinder to rule out a bad replacement, but that code could be bad injector or a a problem in the circuit. If the problem doesn't follow the injector, you need to check the wiring. Might want to invest in an injector noid test light to make it easier to diagnose.

[Mmorajr69]

Thank you for the reply, I cant imagine that the new AC Delco Injector would be bad and I did use the Noid light to check the circuits and they were good, its just odd, maybe it is a new MAF sensor that I need since I only cleaned the current one.

[gtstorey]

Sorry, missed seeing the part about already using noid light.

There really isn't way the MAF sensor, or for that matter plugs and wires, can cause this code. The ECM is not seeing the electrical signature of a functioning injector. This really narrows it down to injector, wiring or ECM. My guess is an intermittent wiring problem.

I will add this is based upon an internet search for the P0203 code description. I will try and confirm the description this evening in the service manual.

[gtstorey]

Following up. The service manual confirms P0203 is injector, wiring or ECM.

[Marvin_Rall]

It seems like you have already taken some of the common steps to diagnose the issue, since the fuel injector, spark plugs and wires, MAF sensor, and injector circuit have been checked. The next steps you could take would be to inspect the vacuum system for any leaks, check the fuel pressure, and possibly inspect the wiring harness and connections related to the fuel injectors. Additionally, you could have a professional diagnose the issue with a scan tool to gather more data on what could be causing the hesitation.

[dmont1011]

Okay so this is my first time posting on here and don’t know how to make a thread or even as a question. So I’m sorry if this is correct but I have a 2011 ls v6 with long tube headers, cold air, high flow cats and exhaust with tune and I’m still throwing a check engine light. It comes up as running to rich. I’ve changed coil packs and spark plugs with just oem spec plugs and that probably the issue but don’t wanna spend 300 on plugs if I don’t have too… please help lol

[ZL1_Chris]

Originally Posted by Mmorajr69

I am sorry if this thread has been talked about before but I was not able to find it.
I have a 2011 Camaro SS with 66,000 miles with manual transmission and recently the car started to hesitate when I started out driving in 1st gear and through 2nd once the car got to higher speed it would smooth out.
The Service Stabilitrak warning came on along with the check engine light
and the car threw a P0203 code which is a Fuel Injector malfunction at the 3rd Cylinder.
I replaced the Injector with a same new AC Delco injector and that didnt resolve the issue so I changed the Spark Plugs and Wires with new NGK Wires and Plugs and that didnt change anything, then I cleaned the MAF sensor and that didnt change anything and lastly I checked the injector circuit with a Noid light and it was performing as it should.
Does anyone have any suggestions as to what else it could be or that I can check.

Hard to say for certain but sounds like an unmetered air leak of some sort like a bad gasket or cracked intake. I'd use hp tuners or similar to get some data first or just continue to guess 🤔....

[Arogg]

Originally Posted by dmont1011

Okay so this is my first time posting on here and don’t know how to make a thread or even as a question. So I’m sorry if this is correct but I have a 2011 ls v6 with long tube headers, cold air, high flow cats and exhaust with tune and I’m still throwing a check engine light. It comes up as running to rich. I’ve changed coil packs and spark plugs with just oem spec plugs and that probably the issue but don’t wanna spend 300 on plugs if I don’t have too… please help lol

Sounds like the tune needs work

[Mmorajr69]

Originally Posted by Marvin_Rall

It seems like you have already taken some of the common steps to diagnose the issue, since the fuel injector, spark plugs and wires, MAF sensor, and injector circuit have been checked. The next steps you could take would be to inspect the vacuum system for any leaks, check the fuel pressure, and possibly inspect the wiring harness and connections related to the fuel injectors. Additionally, you could have a professional diagnose the issue with a scan tool to gather more data on what could be causing the hesitation.

I ended up taking it to an Auto repair shop, and they told me they checked the new injector, the wiring harness, and did other diagnostics and connection checks but found no issue with any so they are going to test the ECM to see if there is anything faulty. This shop is a very reputable shop with a lot of great reviews so hopefully I will hear back today, its just strange that this seems so simple due to the code yet so difficult to pinpoint the issue and I hope its not the ECM.

[Mouse330]

Check the wiring in the harness above the thermostat where the steel clamp is that bolts to the cylinder head

[bottletalk]

usually an ecm fail will take out a bank not one single injector.
get a second opinion if they want to replace the ecm, it's very easy to check right to the pin connection on the ecm and the internal from the pin to the board which could be loose.

[Mouse330]

The ECM will not take out a whole bank, Fuse 10 powers bank 1, Fuse 9 powers bank 2, Each injector has its own driver/circuit

[Danial]

Originally Posted by ZL1_Chris

Hard to say for certain but sounds like an unmetered air leak of some sort like a bad gasket or cracked intake. I'd use hp tuners or similar to get some data first or just continue to guess ��....

I'd look at the air box for cracks for sure! Had this exact issue pop up a few months ago on my 2013 SS. Took it to the dealer and it was in-fact, a cracked airbox.