Noob questions/need a little bit of help

[countrycorey]

Just got an 02 Yukon and have a few questions.
1. Got the following codes: PO420, B0434, P0442, what are they and how do I about fixing them?

2. What mods are recommended for reliability, performance, and mileage?

Thanks,
Corey


2007 Chevy Classic CCSB LS 4x4 w/ LBZ & 6 Spd Ally
Greystone Metallic
295/70/17 Nitto Trail Grapplers on Chrome H2s w/ LMM Centers
Roll N Lock Bed Cover
Grizzly Nerf Bars
Pioneer 4100 Head Unit
JL Audio Components
Sportsman Max4 Seat Covers
Banks RamAir Intake
Tinted Windows
MBRP 5" DP Back...What cat:dontknow:
PCV Rerouted
EGR Blocker & Fingerstick
Retro Solutions 6000K in Low Beams
Nicktane 1 Micron Filter & Adapter
Banks Intercooler Tube
AutoMeter Phantom II Boost and EGT on A-Pillar
Hammerhead Armor Replacement Front Bumper
EFILive from IdahoRob

 

[commander strax]

google says

Possible PO420 code causes

The following engine related problems are known to generate the PO420 code:

Intake manifold air leaks
Fuel injector problems (leaks)
Incorrect spark plugs
Ignition timing
EGR problem
Defective catalytic converter
Oil or antifreeze entering exhaust
O2 sensor not operating correctly
Road damage to converter
Silicone contamination

 

[countrycorey]

Did some digging and found these. Any direction on what I need to do to fix the issue, and what the third code is?

Corey

 

[SLCHOE]

Just got an 02 Yukon and have a few questions.
1. Got the following codes: PO420, B0434, P0442, what are they and how do I about fixing them?

2. What mods are recommended for reliability, performance, and mileage?

Thanks,
Corey

P0420 - If you have the original catalytic converter on Bank 1, it is most likely bad. You can compare the voltages of the upstream and downstream O2 sensors on that bank with a scan tool to verify. If the downstream is switching up/down mV just like the upstream, the cat is doing nothing. In this case cat will have to be replaced. If the downstream sensor is not switching at all but stuck at a certain voltage, it is almost definitely a bad downstream O2 sensor.

P0442 - I wouldn't worry about this one yet. These easily get triggered by leaving the gas cap loose. Clear the code and make sure you check the gasket on the gas cap. If it's ok, just make sure you seal the cap everytime you put gas in the truck. If it comes back, then you have an EVAP leak somewhere.

B0434 - Common issue. You need one of these http://www.amazon.com/ACDelco-15-73506-Original-Equipment-Conditioning/dp/B000S2SHZK

It's the control module for the rear HVAC. It's behind the right-rear plastic panel by the third row seats. Not hard to get to. 1 hr tops to swap out. Then disconnect your battery or pull the HVAC fuses and relays and let it sit a few minutes. Reconnect battery or plug everything back in, turn the key to "ON" and let the HVAC do it's thing for a few minutes more (recalibration procedure).

 

[countrycorey]

P0420 - If you have the original catalytic converter on Bank 1, it is most likely bad. You can compare the voltages of the upstream and downstream O2 sensors on that bank with a scan tool to verify. If the downstream is switching up/down mV just like the upstream, the cat is doing nothing. In this case cat will have to be replaced. If the downstream sensor is not switching at all but stuck at a certain voltage, it is almost definitely a bad downstream O2 sensor.

P0442 - I wouldn't worry about this one yet. These easily get triggered by leaving the gas cap loose. Clear the code and make sure you check the gasket on the gas cap. If it's ok, just make sure you seal the cap everytime you put gas in the truck. If it comes back, then you have an EVAP leak somewhere.

B0434 - Common issue. You need one of these http://www.amazon.com/ACDelco-15-73506-Original-Equipment-Conditioning/dp/B000S2SHZK

It's the control module for the rear HVAC. It's behind the right-rear plastic panel by the third row seats. Not hard to get to. 1 hr tops to swap out. Then disconnect your battery or pull the HVAC fuses and relays and let it sit a few minutes. Reconnect battery or plug everything back in, turn the key to "ON" and let the HVAC do it's thing for a few minutes more (recalibration procedure).

Thanks for the info. Who would have a scan tool, dealer or any shop?


Corey

 

[SLCHOE]

Thanks for the info. Who would have a scan tool, dealer or any shop?


Corey

Any decent shop should have an OEM level scantool for GM vehicles. Although you can purchase "code-reader" type tools for $100-$300 that will provide "live" data and that will show you readings from most of your sensors.

 

[middelgriff1]

autozone and advanced autoparts can read and clear codes

 

[SLCHOE]

autozone and advanced autoparts can read and clear codes

He needs live data.

You can get one of these ELM327 bluetooth interfaces here: http://www.amazon.com/s/ref=nb_sb_n...ield-keywords=elm327&sprefix=elm32,automotive (forget which one I bought but they are basically all the same Chines crap indifferent packaging). This and download Torque Pro for Android/iOS and you can get a pretty good code reader that also provides live data.

 

[ccapehartusarmyINF.(ret)]

definatly go with the ELM327 get the one made by BATF they are the original creators of the ELM327 anyothers out there are knock offs they are 20 bucks on amazon
ive used the 1200 dollar snap on scan tools at school and these 20 dollar elm 327s used with an android or an iphone or a laptop are just as good

---------- Post added at 08:19 PM ---------- Previous post was at 08:13 PM ----------

if you have anytrouble fixing the evap system let me know in the process of fixing mine i became somewhat of an expert hopefully its just yer gas cap if not it can be a pain in the ass to figure out unless u have acces to a smoke machine most people dont because they are expensive