Whassup everyone!

Wassup everyone!

I'm hoping that someone can help me out. I have a 99' 4runner 4wd and I have been getting a continuous PO172 code (bank 1 running rich). I have changed everything that I can think of: spark plugs, sp wires, MAF sensor, front and rear O2 sensors, fuel pump, fuel injectors, coils ...I believe that's all of it. But the check engine light always goes back on after I clear the code. Normally, it would go back on when it is cleared and then when I shut off the truck, then restart it. It doesn't matter if it's a short or long distance, it will go back on reading PO172. Any ideas?

 

You have to pressure test the system. Smoke it all the way from the air box and see if any parts or the plumbing thru the throttle are sucking in air. With the smoke test you can visible see where these leaks are. This is the only way to make sure you are sucking in air thru hoses or holes in the system.

 

welcome

 

How does it run overall? Have you performed compression or leak down test after replacing all of those items?

 

Welcome!

 

Welcome!

 

Welcome

 

welcome