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My 2004 K1500 4.8 4x4 won't pass inspection, codes 420, replaced cat bank 1, code 455 now? I had GM dealership do service bulletin on heater blower motor relay and now "service air bag" light is on as well. Just did a tune up, plugs, wires, tranny,etc. It helped rough idle a lot but still will stall at strange time. I feel it's partially electrical because of bulletin on instrument panel cluster which I learned about after I don't qualify for free replacement due to mileage,(118000) and age. It displays different issues with no specific pattern except for "replace fuel cap" at approx 4-5 miles of driving from a cold start and after tank gets below 1/2 tank. I can't afford to replace/repair I need to troubleshoot 1st. I've asked many mechanics and none of them have heard of my symptoms. Where can I can a detailed diagram of the vacuum and fuel lines so I can check for leaks?

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The only solution I can offer is temporary and could help you at least pass inspection.

  • When you fuel tank is near empty.
  • Fill your car with 3 Gallons regular gasoline and 3 Gallons E85 gasoline.
  • Erase the error codes and drive around for a little while.
  • Then get the inspection done.
  • After you pass inspection fill the car the rest of the way with regular gasoline.

WARNING: This is a last resort effort. Prolonged use of Ethanol (E85) in engines not designed for it can deteriorate rubber fuel lines, oxidize aluminum, and dry gaskets causing them to crack.

Posted on Nov 16, 2013

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Posted on Jan 02, 2017

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SOURCE: Rough idle

Jeep has been having a problem with this. i take it u have a 4.7L or a 3.7L. when the when to fix this problem they should of replaced all the valves (intake and exhaust). theres a tsb on this and the dealer can look it up. even if you paid for the service they will fix it for free cuz it wasn't fixed the first time. take it back to the them and tell the to read the tsb and fix it right.

Posted on May 15, 2008

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SOURCE: 95 GMC Jimmy 4.3l W vin rough idle

My problem was solved when I repaired my 4 wd activation dash switch. The switch was contacting on 2WD & 4HI at the same time. The front differential activation is vacuum activated possibly creating a tug of war that didn't actually engage it but drained off vacuum from the engine? A theory at best but stumbbled across it because I knew the switch wasn't working properly I repaired it and low and behold rough idle disappeared and all is good for 3 weeks running.

Posted on Dec 10, 2008

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SOURCE: 1989 Corvette starting and idle problems

my 89 corvette is hard to start when it is cold, and runs very rough for about a minute. replaced the IAC and Maf sensors had the throttle body cleaned, now it idles very high and emits the same problems. i also had the injectors cleaned.

Posted on Sep 19, 2009

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P1884 code 2005suzuki forenza P0420 P0134 P0138

code p 420 refers to cat converter system , bank 1--efficiency below threshold ===causes ---cat converter faulty---wiring --heated oxygen sensor (HO2S), 2 faulty
code p 0134 refers to HO2S 1 bank 1-no activity detected ===causes --wiring open circuit -- heating inoperative --- HO2S
also refers to oxygen sensor ( O2S) 1 bank 1--no activity detected == causes wiring ---O2S
code p 0138 refers to HO2S 2 bank 1--high voltage === causes ---wiring short to positive ---HO2S--- ECM
also refers to O2S 2 bank 1 high voltage === wiring short to positive O2S -- ECM
I do not have a listing for code p 1338 but I suspect that it will refer to the other codes in some way
first fix is to check the cat converter is operational ( not cracked and blocking the exhaust system)
next replace the HO2S sensor ( one before the cat converter ) and then the O2 sensor (the one after the cat converter)
all the codes will relate to problems in that area

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1 Answer

How do I troubleshoot code P0420 and pass emissions

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try the sensor first as they are cheaper than a cat

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How do I pass vehicle inspection O2 Cat. Evap for a 2004 Chevrolet Cavelier

What was the code given..
02 will mostly sensors..
Cat code 420 will need new cat
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1 Answer

My 2004 K1500 4.8 4x4 won't pass inspection, codes 420, replaced cat bank 1, code 455 now? Just did a tune up, plugs, wires, tranny,etc.

P0455 Evaporative Emission Control System -Leak Detected (Large Leak)

Would appear you have perished hose somewhere along the line but where ? you would need to do a complete inspection to find it ,no idea even where to look with vehicle as not many here in spain .Now as for airbag light well this is a different ball game here but a lot of vehicles will show the light if the battery goes flat and they need resetting with the right software so consult a local mechanic on this on but do check the wires under the seat as you would be surprissed how many time i have found empty bottles and junk under the front seats which have dislodged the multiplug connection

Nov 16, 2013 | GMC Cars & Trucks

1 Answer

I have a 2004 Ford F150 4x4 Lariat with 99,949 miles on it. The truck started shuddering about 1 month ago after replacing the serpentine belt. A mechanic suggested that I change the spark plugs using OEM...

code p 0021 refers to camshaft position sensor (CMP), intake /left /front , bank 2--timing over advanced /system performance ====causes --valve timing---engine mechanical fault -- CMP actuator
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code p 0345 refers to CMP sensor A bank 2--circuit malfunction===causes wiring ---CMP sensor ECM
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code p 0171 refers to system too lean bank 1===causes --intake /exhaust system leak---AIR system---MAF/VAF sensor ---fuel pressure /pump---injector/s ---HO2S in the bank 1 exhaust manifold before the cat converter
find an accredited service center with experience on the vehicle and have it fixed

Apr 18, 2017 | 2004 Ford F150

2 Answers

I just got the code po 420 how do i fix it

Most likely a worn out exhaust converter

PO 420 -- Catalyst System Efficiency Below Threshold (Bank 1)
that is the right or pass side

Rear or Monitor Sensors could be bad ,if converter is less
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Aug 06, 2011 | 1996 Ford Explorer

2 Answers

I got a diagnostic test and came up code p0420. what should i do to fix the code for it to pass ommissions test?

Replace the 02 sensor bank 1. Although there was a service bulletin for your year car. Ask your dealer about it. Also might be covered under warranty

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1 Answer

Keep getting po155 code even after replacing 02 sensor several times with new one from dodge. Had transmission replaced under warranty and have been chasing 02 sensors ever since. All but 1 has been...

this code is for bank 2 sensor 1 only. You need to inspect the wiring harness. Chances are it was damaged when the trans was worked on. Check both sides for the same signals, Both 02 sensors before the cat. If there not the same on voltage then thats where the problem is.

You should have 12v on on of the heater wire and a ground on the other with the key on.. The wires for the heater should be the same color ones. Or you can go to mitchell1diy and for ten bucks get the diagnostic procedures and wiring diagrams.

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Trouble code 00P38 on a 2004 dodge 2500

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