Question about 1999 GMC Yukon

2 Answers

Po420 twc system low bank 1 code - 1999 GMC Yukon

Posted by on

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,129 Answers

Vehicle needs a Primary or first position Oxygen sensor, bank one just means it's the O2 sensor before catalytic converter

Posted on Jul 02, 2009

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

I have 1998 gmc pick up truck and has code po 420

Posted on Dec 23, 2009

2 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

  • 1608 Answers

SOURCE: 1998 grand am 2.4 liter, engine code po420 (twc

What this means is that the three way catalytic converter is not doing it`s job and it needs to be replaced.First check the exhaust system and make sure it is not bent or has holes.If it`s good then make sure the rear o2 sensor is working properly.If that`s good the you will have to replace the cat.converter.Good luck.

Posted on Dec 06, 2009

Testimonial: "that was an amazingly fast...I'm going to have my brother check that out this week...thank you so very much. "

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Dodge caravan 07 3.3L V6 have trouble code P0420


Generally speaking the catalytic converter is worn out and the system reads this and sets the code P0420

Nov 01, 2012 | Dodge Cars & Trucks

1 Answer

What does a ******** Catalyst(TWC) system, low efficency service code mean? and where is it located


Exhaust Converter on Bank #1 side, is worn out,needs
to be replaced

PO420 &PO430 are Converters Below Efficiency

Should have lasted another year or two

I suspect you don't keep up on what the car
required,air filter,spark plugs,O2 Sensors & the like.

Your fuel trim & ignition issues over the years ruined it

Jun 02, 2012 | 2001 Cadillac Seville

3 Answers

Diagnostic trouble codes dtc po420 po102


CODE PO102 IS MAF SENSOR CIRCUIT LOW FREQUENCY CONDITIONS / CODE PO420 IS CATALYST SYSTEM LOW EFFICIENCY BANK 1 CONDITIONS. BAD MASS AIR FLOW SENSOR WILL AFFECT CONTAMINATE DAMAGE CATALYTIC CONVERTER DUE TO RICH EXHAUST EMISSIONS.

Jan 26, 2011 | 1997 GMC Jimmy

1 Answer

1997 mercury sable po 420 bank 1 which sensor do i change.


That could be the cataylic convetor you could try the oxygen sensor behind the cat the last one to the rear of the vehicle bank 1 sensor # 3 but P0420 is TWC system witch means low efficiency in the cat but it could be a sympthom of an other problem but if the code is 0420 thats where i would start

Nov 17, 2010 | Mercury Sable Cars & Trucks

2 Answers

P0420 code on my 2003 chevy s10


please go to the provide link for diagnosis of this code,but the bottom line here is the catalytic converter may be worn out

http://www.p0420.com/

Aug 06, 2010 | 2003 Chevrolet S-10

1 Answer

What is this code po420 bank 1 in a che?vy monte


I could go on and on about Po420 code but it's easyer to tell you to go to www.po420.com and everything you want to know and then some is there. Let me know if this was helpfull..4 thumbs up !

Feb 24, 2010 | 2002 Chevrolet Monte Carlo

2 Answers

1998 grand am 2.4 liter, engine code po420 (twc system low efficiencty bank 1) what does this code mean


Catalyst System Efficiency Below Threshold Bank 1
this is code P0420.
It's telling you converter is not as efficient as it should be.You can drive it like this forever,or spend to replace a converter.

Dec 06, 2009 | 1998 Pontiac Grand Am

3 Answers

1998 saturn check engine lite comes on gives codepo420&po573


Code po573 is cruise control / brake switch circuit A circuit voltage high PO420 catalyst system below threshold, po573 is probably a bad brake circuit / switch problem, PO420 is a bad catalatic convertor for bank 1

Sep 28, 2009 | 1998 Saturn SC

1 Answer

1997 toyota camry check engine light on,code po440,po420,po441,


P0420 is catalyst system efficiency below threshold (bank 1)

P0440 is evaporative emission control system malfunction

P0441 is evaporative emission control system incorrect purge flow

Mar 29, 2009 | 1997 Toyota Camry

1 Answer

PO420" Catalyst efficiency low Bank 1"


Replace the catalytic converter.

Mar 09, 2009 | 1999 Acura TL

Not finding what you are looking for?
1999 GMC Yukon Logo

Related Topics:

667 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

75822 Answers

Freddy

Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...