Check Engine Light - Error Code= P0202

[Ratical2]

The engine began running a little rough on Friday. The scan showed P0202- Injector circuit open- Cylinder2. I checked to see that each injector was receiving the signal and they were so the problem lies with the injector.

Is there a cleaning process or does the injector need to be replaced?

The engine is a stock 96 with 31K miles.

Thanks

[AZTVR]

Originally Posted by Ratical2

Is there a cleaning process or does the injector need to be replaced?

Someone else will probably have a comment about cleaning methods while they are on the car; but, I've used this guy Fuel Injector Cleaning and Blueprinting to service injectors from a different vehicle. He was very professional, giving before and after test results.

[Ratical2]

Hi Jim, Thank you for the link!

[SYNFULL]

You should check with Tony Armour - a member and sponsor on the board. I know he cleans and tests injectors. I don't know his web address but you can search the board. His nic is 1Tony1

[kcobean]

Injector flow bench/cleaner up and running

[AZTVR]

Originally Posted by Ratical2

The engine began running a little rough on Friday. The scan showed P0202- Injector circuit open- Cylinder2. I checked to see that each injector was receiving the signal and they were so the problem lies with the injector.

Sorry, after rereading, I realize that I lost sight of your original problem. Have you measured the resistance of the suspect injector and compared to some good ones? I'd do that first, to make sure that you don't have an injector that has failed electrically, or possibly a bad connection. That's what the error code implies.

If you suspect dirty injectors, I'd certainly suggest going to 1Tony1. I didn't remember that he was set up for that service.

[dave6666]

Redneck injector cleaner method:

-> Purchase 6-pack Lone Star long necks.

-> Open one. Pour on head.

-> Drink other five.

-> Restart car.

[AZTVR]

Originally Posted by dave6666

Redneck injector cleaner method:

-> Purchase 6-pack Lone Star long necks.

-> Open one. Pour on head.

-> Drink other five.

-> Restart car.

I think that you may be talking about cleaning out a different injector ?

[Ratical2]

Dave you crack me up. That is an entirely different process!

I am kinda new to OBD diagnostics. I realised the reason I have codes thrown for all 10 cyclinders. I pulled the connector and placed a neon test light to verify each injector was getting a signal. I am sure this is why I have the Open ckt code for each of the 10 cylinders. I am going to measure the resistance of each injector has suggested and clean each connector then erase the codes to see if they return.

I would guess the other areas to investigate for the miss would be:
1. spark plugs -but I replaced them 3 weeks ago. Performace seem to improve until this weekend.
2. Spark plug wires- replaced them last year about 10k miles ago. They are MSD's. In the dark with the engine running, I didn't see any sparks are arching to indicate the plug wires were bad.
3. Compression check.

Am I missing anything?

[Ratical2]

I ran the scan again and no more DTC Codes come up. The injector error codes have not returned. So, my guess the injectors are fine. However the Scanner also test for MIL Status and Catalyst Monitor is flashing. The scanner manual states:
"The computer commands the MIL "on" when the failure is first found. If the failure causes a severe misfire that may cause damage to the catalytic converter, the MIL " flashes" once per second. The MIL continues to flash as long as the condition exists. If the condition that caused the MIL to flash is no longer present, the MIL will light "steady" on."

Mine is flashing at one second intervals.

My question, can the O2 sensors be bad without tripping the DTC error code?

If the O2 sensors are indeed bad, that could create a too rich condition, cause the rough running engine at low rpm. This could also be the cause why the catalytic monitor has not reset.

I just read this, the Viper Service Manual states, " When the catalytic converter efficency drops below emission standards, the PCM stores a diagnostic trouble code and illuminates the Malfunction Indicator Lamp (MIL).

Since this hasn't reset it looks like I need new cats and possibly O2 sensors...

Suggestions anyone?

[dave6666]

Originally Posted by Ratical2

Suggestions anyone?

Sometimes, an intelligent sequence of parts replacements becomes the strategy to solve the problem.

O2 sensors wear out and are not terribly expensive or hard to change. If you suspect them and are short on other ideas, then yes, I would get new ones.

The cats are a little harder to change, and might be second on the list. But a question... Since the rear sensors, assuming your car has them, don't measure cat performance, the only thing that can truly determine whether they are good or not is a sniffer right? Aren't those at every street corner in CA?

Sorry, that last comment was inappropriate.



Anyway, the diagnostics might be generic, meaning that under these conditions the cats could be bad. But that is not based on measuring cat performance in the Gen 2 Viper, just a set of generic conditions that some scientist or engineer designed into the system.

So I would as said do the sensors first if you suspect them, and then stop at the Quikie Mart for a soda and sniff test some day.

EDIT...

I think what I should clarify, and someone might chime in if I'm still incorrect, is that the rear O2 sensors do monitor cat performance, but they don't tune or adjust A/F with that data. Therefore cat performance is passive information, and may or may not mean the cats are good or bad, since it really does not try to fix the problem if found. Like by leaning the engine out some before pulling a WTF dude, we think your cats are bad.

[Ratical2]

Thanks Dave,
I was using this as sounding board to make sure I wasn't missing something obvious. I would definitely change the O2 sensors first. Heck of lot cheaper and easier before I would change the cats. The car has 32K miles and I am not sure if it has the original cats or not as the sidesills seem to have been off at one time. I have never had a cat fail in any of my cars before 100K miles.

You are right about the sniffers. I seem to recall there used be portable units going around spot checking people for compliance. I don't remember the details.