cel 41, no RH O2(front?) only in some cases.

[Alan92RTTT]

In the morning heading to work the car runs fine.
When I stop for pop the rest of the trip in is fine.
In the evening on the way home its fine.
After the drive home if it sites about 30 minutes its starts throwing a CEL.

Pocketlogger says its a code 41 injector circuit.
When this is happening I'm not getting a cycle on the RH (front) O2
If I disable the injectors one by one Disabling #3 has no effect.


Suggestions?

[Emilie@GZP]

Most likely your ecu.

[Alan92RTTT]

Any other suggestions.

I'll pull it after work tomorrow and see what I see.

[RealMcCoy]

I agree an injector driver in the ECU is very likely, the second most common possibility would be the #3 injector. That is really easy to check since the ECU is seeing a circuit problem. Just get it warm where it's having the issue, and put an ohmmeter across the injector. It will most likely have very high resistance if it is the cause of the problem. Since #3 is the center front injector, access is really easy, so that's probably the first thing I'd eliminate before pulling the ECU...

[Alan92RTTT]

What is considered "high"

Please explain "put an ohmmeter across the injector." in word someone that clueless about electrical would understand.

[RealMcCoy]

When you unplug the injector, there are two terminals in the connector. You are measuring the internal resistance of the coil in the injector. You would hook each lead of your ohmmeter to a terminal and take a reading. TT injectors are around 2.5(ish) ohms... To set a code, I would expect it to be several times that.

[Alan92RTTT]

Just to make 100% sure.

Get error code.
Shut off car
pull #3 injector clip
check resistance on injector


No change in value for 450cc injectors?

[RealMcCoy]

Just to make 100% sure.

Get error code.
Shut off car
pull #3 injector clip
check resistance on injector


No change in value for 450cc injectors?

Correct... And yes, the DSM 450's have the same specs.

[Alan92RTTT]

I just tested the injectors and I did not get the result I expected.

I do not think I had the meter set right and its an old one that was my Dads. I know it was on Ohms I know that symbol.

Open it showed 10.000 with the 1 blinking.

Imo this says the injector is messed up. I left everything disconnected and I will go out later and check again and again in the AM.

On the injector closest to the trans(for comparison) I got 33(33 what I have no clue)
ON #3 it did not change from the open state.

[RealMcCoy]

If the injector is going full open that would be an issue... 33 Ohms is also too high, you may have more than one with a problem.

Connect the leads of the meter together and make sure it goes to zero, then try the third injector in that bank to see if it shows a normal reading.