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00 4cyl Camry, 195k miles Cali emissions
A few months and almost 2000 miles ago had P0420. Replaced cats with Cali approved Bosal, and also replaced both sensors with Denso.
Cleared codes, set readiness, has been fine until last night. P0420 returned! My NY inspection is due so I need to get this repaired.
I’ve read that intake leak and injectors can also cause this. I smoked it and found this crack. Would this cause P0420? No other codes current or pending. I have ordered this tube, but won’t be here until tomorrow. I’d like to check other items while waiting, if possible.
How can I check if an injector is leaking?
What else can I check for causing this code?
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You say you found a crack?
Where exactly?See if this helps ….
http://www.easterncatalytic.com/education/tech-tips/the-misleading-nature-of-the-po42o-code/
As to leaking injectors ..
You’ll need to put a fuel pressure gauge on the fuel supply line.
Providing the rest of the fuel system is functioning correctly, after running the vehicle, the gauge should show maintaining pressure after the engine is switched off.
If the pressure drops off quickly you either have a leaking injector, bad pressure regulator or bad check valve in the fuel pump.
Or possibly some combination.You found a crack in what?
Which catalytic converter did you replace–the manifold cat or the one closest to the muffler?
Since you have a scan tool, what are the fuel trims at idle?
Raise the RPM to 2500 for 30 seconds and record the fuel trims at the end of the 30 seconds.
What are they?
Fuel injector stuck open will cause fuel pressure to drop quickly after the vehicle is shut off.
You need a fuel pressure tester to check, of course.
It wouldn’t be a bad idea to see if your fuel pressure regulator is working properly.
When they break, the excessive fuel pressure can cause a rich condition.Started writing was called away, clicked post—and just saw the post above mine LOL 🙂
Trying to attach from a different computer, was getting fatal error before.
You can see the smoke coming out of the crack by the clamp
EDIT: Photo won’t attach
The crack is on the airbox tube from the box to the throttle body. The crack is large and right before the clamp that holds the tube to the throttlebody
I got excited and have almost taken the fuel rail completely out, going to see if an injector is drooling. Then will reassemble with new orings and check fuel trim and pressure. Doesn’t look like there is an easy pressure connector so hooking that up may take me a while 🙁
I keep getting fatal error from both computer when I try to attach a picture!
The crack is on the airbox tube from the box to the throttle body. The crack is large and right before the clamp that holds the tube to the throttlebody
That is called “pirate” air.
That is air going into the engine not measured by the MAF sensor and figured in by the vehicles computer to adjust the fuel mixture which will see it as the engine running lean and try to add fuel to compensate.
This will cause issues with your fuel trims.
You need to correct that issue first.[quote=”Elle” post=185401]I got excited and have almost taken the fuel rail completely out, going to see if an injector is drooling. Then will reassemble with new orings and check fuel trim and pressure. Doesn’t look like there is an easy pressure connector so hooking that up may take me a while 🙁
I keep getting fatal error from both computer when I try to attach a picture![/quote]
I would not be taking anything apart until you correct the issue with the air intake tube and drive the car for a bit
Then check your short and long term fuel trims and see what readings you get.
As to the fuel pressure connection.
You may need to cobble a TEE fitting together for your specific setup, not uncommon .To properly test fuel pressure you need a special banjo adapter and bolt which goes on the fuel filter… Very similar to the pic
OK fuel pressure does not drop after shut off. I took a video of the gauge. If need be I’ll make a photobucket account or something. I have tried different computers but I can’t upload files.
Freeze frame fuel trim:
ST -7.0
LT 3.1Closed Loop
Speed 37
Intake Temp 42
ECT 188Toyota Karl, I love your avatar haha. Just watched again the other night. “I’ve come to fix your cable.” haha
Long term fuel trim is adding fuel to compensate for additional air.
Trims should be close to 0 if everything is working correctly.
Have you repaired the inlet tube leak?The new intake tube will be here tomorrow or Sunday, so I guess I’ll report back then. Thanks so much for your help. I’m going to try to figure out how to post photos now haha
New intake tube replaced. Also found upper resonator tube had torn, so replaced that (whole resonator with tube).
Fuel trim at idle
ST -0.8
LT 18.82000 rpm
-3.1
LT 15.6I’m reading long term can take up to ten miles to reset itself. I’m going to drive it tonight and see if still high. If not, back to looking for a leak.
Not 100% sure how many miles driving it will take.
Worse case, you can disconnect the positive battery cable and ground it for a while and do a computer reset, then drive around a bit.
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