catalytic function not clearing (should I do more parts cannon)

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

OP
OP
Fernando Escobar
Joined
Aug 30, 2018
Posts
61
Reaction score
47
Location
Los Angeles, CA
thank for the info, So I guess It a major rich fuel issue. I could not find my newer more detailed scanner but even my old one gave me some much valuable data My LTFT on Bank 2 is above 10% (13.3 to be exact) which i guess to much of the dark web info out there is in the rich territory. So I guess a look at my fuel injectors and MAF is on the check list to check.
 

Attachments

  • IMG_7282.jpeg
    IMG_7282.jpeg
    351.1 KB · Views: 4
  • IMG_7281.jpeg
    IMG_7281.jpeg
    385.2 KB · Views: 4

nonickatall

Full Access Member
Joined
Nov 19, 2022
Posts
628
Reaction score
1,132
Location
Germany
I would first check the fuel pressure. The fuel pressure valve is a cheap, easy to swap part. And a wrong fuel pressure can cause this because:

The necessary injection quantity is calculated by the ECM, which depends on the amount of air sucked in, the data from the o2 sensor, the revolution speed of the engine, the throttle position, the engine temperature and so on, and realized by the fact that the injection valves are opened for a certain time.

In order for the injection quantity to be correct, there must be a defined fuel pressure in the injection rail.

This works so that fuel pressure comes from the rear fuel pump, which is applied to the injection rail and is released again in a controlled manner by the fuel pressure valve in order to achieve the necessary pressure.

If this small component is worn out and the correct fuel pressure is no longer present, or the fuel pump no longer delivers the correct amount of fuel, the injection quantity is no longer correct, then nothing is correct...

There is a small valve in front at the fuel rail, where you can measure the fuel pressure with a propriate gauge.

And ask yourself if your car has a fuel filter and when you changed it for maintenance....
 
Last edited:
OP
OP
Fernando Escobar
Joined
Aug 30, 2018
Posts
61
Reaction score
47
Location
Los Angeles, CA
I would first check the fuel pressure. The pressure regulator vent is a cheap, easy to swap part. And a wrong fuel pressure can cause this because:

The injection deficiencies calculated by the ECM, which depend on the amount of air sucked in, the data from the o2 sensor, the revolution speed, the throttle position, the engine temperature and so on, are realized by the fact that the injection valves are opened for a certain time.

In order for the injection quantity to be correct, there must be a defined fuel pressure in the injection rail.

This works so that fuel pressure comes from the rear fuel pump, which is applied to the injection rail and is released again in a controlled manner by the fuel pressure valve in order to achieve the necessary pressure.

If this small component is worn out and the correct fuel pressure is no longer present, or the fuel pump no longer delivers the correct amount of fuel, the injection quantity is no longer correct, then nothing is correct...

There is a small valve in front at the fuel rail, where you can measure the fuel pressure with a propriate gauge.
the pressure is at 45-50 at start up. I might do a leak down test to see how long that pressure holds. that could help me determine if the injectors are bad.
The Pump was changed a few years back as well. along with the fuel pressure regulator diaphragm and the stupid little hope that goes to the regulator to the sensor. It was expensive and difficult to find
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
10,474
Reaction score
20,821
Location
Elev 5,280
Positive fuel trims means that it's adding fuel, which indicates the O2 sensors are reporting a lean condition.

However, your STFTs look okay, especially if that's at idle (couldn't tell the rpm from the pics). Get a scanner that can reset the LTFTs and start monitoring it after a drive cycle or two.
 
OP
OP
Fernando Escobar
Joined
Aug 30, 2018
Posts
61
Reaction score
47
Location
Los Angeles, CA
Positive fuel trims means that it's adding fuel, which indicates the O2 sensors are reporting a lean condition.

However, your STFTs look okay, especially if that's at idle (couldn't tell the rpm from the pics). Get a scanner that can reset the LTFTs and start monitoring it after a drive cycle or two.
I took out the spark ugs chasing this lean condition. I measured some of them at .080!!! Twice the amount required. Its running better now still need to tune it. But hopefully this at least clears the monitors for smog!!!
 

Attachments

  • IMG_7289.jpeg
    IMG_7289.jpeg
    305.6 KB · Views: 5

nonickatall

Full Access Member
Joined
Nov 19, 2022
Posts
628
Reaction score
1,132
Location
Germany
I took out the spark ugs chasing this lean condition. I measured some of them at .080!!! Twice the amount required. Its running better now still need to tune it. But hopefully this at least clears the monitors for smog!!!
A lack of maintenance might be one of your problems.

Your P0300 can come from that.

Did you change your air and fuel filter as well?

I would start with a simple maintenance...
 
Last edited:

TollKeeper

Full Access Member
Joined
Feb 21, 2010
Posts
2,731
Reaction score
5,232
Location
Brighton, CO
I took out the spark ugs chasing this lean condition. I measured some of them at .080!!! Twice the amount required. Its running better now still need to tune it. But hopefully this at least clears the monitors for smog!!!
Are those counterfeit plugs? I dont see a Iridium tip on those.
 
OP
OP
Fernando Escobar
Joined
Aug 30, 2018
Posts
61
Reaction score
47
Location
Los Angeles, CA
They were supposed to be the basic platinum oem plug.
But they very well could have been counterfeit. the gaps were all over the place and now seeing the gap widened by .035in.
The engine is purring again. I hope this was my issue now on to smog and get it tunned.
 

Forum statistics

Threads
129,239
Posts
1,812,630
Members
92,339
Latest member
Thekenstar

Latest posts

Top