SaturnFans.com
what's new (beta) - classifieds - forums - photos


Go Back   SaturnFans.com Forums > Models > Saturn Ion > Ion General
Register FAQ Members List Groups Calendar Chat Room Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 08-13-2019, 08:50 PM   #1
Xander889
New Member
Xander889 is on a distinguished road
 
Join Date: Aug 2019
Posts: 3
Default P0420 Issue

Hi,

I am having an issue with an 07 ion 2.4l. It is throwing the P0420 catalyst below threshold. 02 sensors have been replaced. Upstream reads a bouncing voltage from .2-7, with a +- 5-7% STFT. Downstream is a constant 99.2% (assuming it has nothing to do with fuel trim and readings come from the upstream) and a .67 voltage. (Live data)... Thrown code read an upstream of 0.0% STFT, and LTFT of -2.3%. So, with these numbers I am assuming that the catalytic converter is fine. Or am I wrong? The cat was replace 4 years ago, and I've had no codes since then other than some fuel trim balance code that comes and goes after some fuel injector cleaner and/or a full tank of high octane fuel.

the dilemma. If it's not the cat or 02 sensors, what else could lead to this code?

Thanks ahead of time!

REWARD EXCELLENCE!

Add to Xander889's Reputation
Rate the quality of this post and help Xander889 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Xander889 is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 08-13-2019, 11:37 PM   #2
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 42,795
 

2003 L-Series 3.0L Sedan
Default Re: P0420 Issue

If I'm not mistaken, P0420 applies to all vehicles using precat and post cat O2 sensors. The precat sensor is the important one as its used in closed loop engine running for adjusting fuel mixtures in compliance with emissions mandates. The post cat sensor is used to monitor catalytic converter efficiency. P0420 usually points to a faulty catcon. The operation of each O2 sensor is different from each other.

The precat O2 sensor monitors combustion directly off the exhaust manifold to provide feedback to the engine computer. The ecm or pcm has emissions programs to run the engine as efficiently as possible to pass federal and state emissions. Closed loop mode is when the engine is at operating temperatures and the O2 sensor is heated from exhaust gases to produce signals. The fluctuating voltages is the frequency of monitoring lean to rich to lean fuel mixtures (oxygen left from combustion). Ideal numbers vary between 0.4-0.8 volts. The catcon, when heated to operating temperatures, converts exhaust byproducts to CO, HC, NOx and water vapor. The downstream O2 sensor monitors catcon efficiency so its output tends to remain steady at one voltage.

With both O2 sensors replaced, either an exhaust leak occurred upstream of the post cat sensor or the catcon is worn out. Damage to catcons can occur with fuel additives not recommended, adding leaded octane booster (lead clogs catcons) or other mods in attempts to generate more power where excessive fuel isn't burned in cylinders and exhausts into the catcon to fuel a higher operating temperature than catcons are designed to run resulting in melting internal components.

REWARD EXCELLENCE!

Add to fdryer's Reputation
Rate the quality of this post and help fdryer reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fdryer is offline   Reply With Quote
Old 08-14-2019, 10:49 AM   #3
Xander889
New Member
Xander889 is on a distinguished road
 
Join Date: Aug 2019
Posts: 3
Default Re: P0420 Issue

Thanks for your response.

It would be surprising to me if the catcon has gone bad in a short time. I do not modify my car and keep it stock performance wise, so this should not be an issue either. hmm, I guess I could have a small leak, but aurally nothing out of the norm can be heard.

Thanks!

REWARD EXCELLENCE!

Add to Xander889's Reputation
Rate the quality of this post and help Xander889 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Xander889 is offline   Reply With Quote
Old 08-14-2019, 07:24 PM   #4
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 42,795
 

2003 L-Series 3.0L Sedan
Default Re: P0420 Issue

Original Saturn warranty was 3 yrs or 36k mikes. Emissions systems including exhaust was 8 yrs or 80k miles. While many choose to cling to outdated long term life on parts long after new car warranties expired on items automatic xmissions, engines, etc, and complain about them failing, the reality has always been once a new vehicle warranty expires, nothing is guaranteed to last forever. Parts wear out whether in or out of warranty. With exhaust systems, GM adopting dull stainless exhaust systems prolonged their lifetime usefulness. This allowed longer warranties on the EFI/emissions/exhaust systems. Since every vehicle manufacturer has zero control on what each driver fills their vehicles with fuel, adds additives from hearsay, old wives tales, afraid of being stranded in the dead of winter or long lonely stretch of road, all manner of fuel treatments winds up as exhaust byproducts that can affect catcon longevity.

REWARD EXCELLENCE!

Add to fdryer's Reputation
Rate the quality of this post and help fdryer reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fdryer is offline   Reply With Quote
Old 08-18-2019, 11:04 AM   #5
Xander889
New Member
Xander889 is on a distinguished road
 
Join Date: Aug 2019
Posts: 3
Default Re: P0420 Issue

Good to know. Thanks for your help!

REWARD EXCELLENCE!

Add to Xander889's Reputation
Rate the quality of this post and help Xander889 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Xander889 is offline   Reply With Quote
Old 08-18-2019, 04:26 PM   #6
ruley73
Master Member
ruley73 is a splendid one to beholdruley73 is a splendid one to beholdruley73 is a splendid one to beholdruley73 is a splendid one to beholdruley73 is a splendid one to beholdruley73 is a splendid one to behold
 
ruley73's Avatar
 
Join Date: Aug 2006
Location: Is this heaven?....No, it's Iowa!
Posts: 2,952
 

2007 ION-2 Quad Coupe
Default Re: P0420 Issue

An exhaust leak in the flex pipe between the exhaust manifold and the downpipe is very possible. They have a very high failure rate in all the Ion, Cobalt, HHR, and G5 cars.

I can tell you from experience that the sound of a leaking flex pipe is very subtle, but definitely audible. You won't hear it unless you know exactly what sound you're listening for. I didn't realize I was hearing mine leak until after it was fixed and the noise disappeared. It sounds like a constant muffled rattle coming from the middle of the firewall that is louder whenever you put your foot on the gas. I think it sounds like beans rubbing the inside of a pair of maracas.

Luckily, there are many companies that offer an inexpensive replacement that can be easily installed by an exhaust shop.

...
2007 Ion 2 Quad Coupe 5-speed manual 181K miles
2007 Chevy Equinox LT 193K miles
2018 Chrysler Pacifica Touring L 36K miles

REWARD EXCELLENCE!

Add to ruley73's Reputation
Rate the quality of this post and help ruley73 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
ruley73 is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
P0420 code, Catalytic Converter Issue dnl Outlook General 6 11-10-2014 08:51 AM
P0420 bigj860 S-Series Tech 17 12-28-2013 09:48 PM
p0420 Homerlasvegas S-Series Tech 20 07-30-2013 11:06 AM
96 SW2 with P0420 kindashort S-Series Tech 11 06-10-2012 08:35 PM
p0420 jheinrich L-Series Tech 5 03-28-2009 04:20 PM


All times are GMT -4. The time now is 10:16 AM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
SaturnFans.com. The Saturn Enthusiasts Site.