someguy85

Hello,

First time poster here.

I've been lurking for a couple of weeks here trying to find information on how I can fix my current issue but no luck.

Problem:

ES300 that was sitting without moving for about 3 years runs really rich and fails SMOG test.

I see that bank 1 (firewall side) seems to be running the richest since I see black sot on the bank 1 header, bank 2 (front of car) headers seems clean (gray instead of black)

The car is pushing a lot on the HC/CO2 side about 7.38% etc.. (Gross Polluter)

Things that have changed since last smog:

Changed 2x O2 Sensors ( Numbers stay the same... )
Changed Catalytic Converter ( Numbers stay the same... )
Changed fuel pressure regulator ( Numbers stay the same... )
Changed ECU ( Numbers stay the same... )

Planned Changes:

Tomorrow I will be move the injectors from bank 2 to bank1 and then install some junkyard injectors on bank 2 since they are easiest to remove, I will then test to see if the problems is fixed due to a faulty or stuck injector.

Any other pointers that you guys can suggest as the possible cause for a rich running car?

Thank you.

mdbrown

High HC is raw fuel. Could be dripping injectors or possibly a bad coolant temp sensor reading cold causing the injectors to stay open longer. How does the car run? What's the reading for idle test vs loaded test?

EEngineer

wow, all these things u did and i don't see sparkplug change.

go change those and the wires asap!

someguy85

Good afternoon guys sorry for the late reply, I had **** to do this morning and I had to wait for the car to cool down and work on it.

I moved the front injectors to the back and installed some new ones from the junkyard in the front car is running fine but it is still running very very rich.

So the theory of stuck injector possibly out of question...

7.36% CO2 (Took it to a friend that reads the numbers for me)


I did change the spark plugs I didn't think that bad spark plugs could cause a rich condition but now that I think about it they can since the fuel may not be burning up correctly.

I'll try the ECU temperature sensor this time and see if this make any difference in how the car runs.

I also did a quick voltage test on OX1 and OX2 in the diagnostic port on the engine bay, OX2 read between 9-10 volts depending on engine load, for some reason OX1 always reads about 12-13 volts.

Both sensors are brand new, if I unplug bank 2 sensor I see a voltage drop to about 4-5 volts on the diag port, however on bank 1 the voltage stays the same regardless on weather the sensor is connected or not.

Maybe a rich condition because of a wire touching ground somewhere?

Thank you.

mdbrown

Yeah, I kinda figured the spark plugs had been changed. You might look at the wires but if it's generally running okay then it's firing okay. Things to consider... fuel pressure. I know you changed the FPR (with a new unit right?) but it has limits. There is also the possibility of a lean misfire. I'll assume again the air filter has been changed. The O2 sensors, are they generic or factory parts? Best way to test the O2 sensor is either streaming data. That would be difficult on this car so I'd recommend getting a pin to puncture the insulation and checking with an older analog volt meter. There should be approx 8-10 crossovers per second (O2 sensors natively put out between .1 and 1 volt. Below .5 volts is a lean condition and .6 to 1 volt is rich.

If the car runs smooth and has no power issues then I'd guess that a lean misfire isn't the issue. Based on your post above I'd trace the wiring on the bank 1 O2 sensor and look for a short.

EEngineer

hmmmm....i was going to say seafoam but at this point i'm not sure if it's going to help at all.

what about the AFM, has it been messed with? maybe find another AFM and try swapping it.

BradTank

I think the big mistake here is just throwing so many parts at a car without doing a real diagnosis. I don't know if the parts you're putting in are from a salvage yard, but if they're new parts, I'm seeing over a $1,000 in guesses. I've been burned on this approach as well in the past, it gets expensive real quick.

What you're describing could be a variety of issues, like a weak ignition coils, spark plugs/wires, leaking fuel injectors, MAF sensor, coolant temp sensor, vacuum leak etc.

I think it would save you a lot of money to have a good tech hook a scanner up to get a better diagnosis of what's going on before you keep guessing, it could be something incredibly simple.

someguy85

Sorry for the delay guys, I managed to make some head way into the possible cause of the car running rich.

Based on the multimeter readings yesterday I decided to directly connect Oxygen sensor 1 to the ECU with a different cable.

I went to the smog shop to run some numbers and the guy told me that the numbers had dropped from 7.5-8.2% CO2 to about 1-2% CO2

So I have a short on the wiring for OX1 just need to find out where.

I'm looking at the wiring diagram diagram PDF and I see that a white wire is supposed to leave from OX1 to the ECU but it also splices into another point going somewhere I can't see in the diagram.

Any Ideas where the spliced end is going too?

Thank you.

Xtom73G

MAF sensor should be a primary target for this issue. Sometimes can be cleaned, but maybe replaced. Did you check out the condition of the air filter? BTW, using K&N type filters and over oiling them can foul the MAF big time.