PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

o2 questions? need help!

Thread Tools
 
Search this Thread
 
Old Mar 1, 2010 | 08:55 PM
  #1  
allan808's Avatar
Thread Starter
TECH Apprentice
iTrader: (3)
 
Joined: Sep 2009
Posts: 388
Likes: 0
Default o2 questions? need help!

my buddy came over and hooked up a guage in the obd2 plug and we looked at the front o2 sensors at idle..the driverside was bouncing from about 100 to 890 the passenger side was between 350 to 500 does that sound right?
is the right side going bad? i have no ses or codes..what do they normally run at on both sides before the cats?

btw i did a search and didnt find what i was looking for..
i got a 98 trans am stock..

also it has a miss here and there and today when starting it backfired then when i reved it up a little it backfired more..after a few minutes it stopped....

thanks a bunch in advance..
Reply
Old Mar 1, 2010 | 09:42 PM
  #2  
racecar's Avatar
TECH Resident
 
Joined: Aug 2004
Posts: 875
Likes: 2
From: Portland Oregon
Default

That sounds a little strange. They are never perfect, but I would expec to see the activity a little closer than that. I would check it again, at idle and at mid range.
They may work better with higher flow. If they have many miles, just replace them. With new ones you will see accurate numbers.
Reply
Old Mar 1, 2010 | 09:59 PM
  #3  
allan808's Avatar
Thread Starter
TECH Apprentice
iTrader: (3)
 
Joined: Sep 2009
Posts: 388
Likes: 0
Default

thanks,would my o2's be causing my issues?
Reply
Old Mar 2, 2010 | 02:19 AM
  #4  
racecar's Avatar
TECH Resident
 
Joined: Aug 2004
Posts: 875
Likes: 2
From: Portland Oregon
Default

If they are old and full of carbon, they can be sending signals to the PCM that are not totally accurate. You really need to see more scanning at cruising speed to be sure.
If you put new ones in, I would bet that you will notice a difference in how the car runs.
How many miles are on the car and the O2s? If the mileage is big, I would check the cylinder compression or leak down, Cyls good, replace spark plugs and O2s. It will run better then.
Reply
Old Mar 2, 2010 | 03:22 AM
  #5  
eseibel67's Avatar
TECH Fanatic
15 Year Member
Photogenic
iTrader: (10)
 
Joined: Feb 2008
Posts: 1,781
Likes: 4
From: Kitchener, ON
Default

Your right O2 is bad. It should be switching like the left one. Double check again with scanner, but at 2000 RPM.
Reply
Old Mar 2, 2010 | 12:30 PM
  #6  
jetblast's Avatar
Launching!
 
Joined: Dec 2005
Posts: 232
Likes: 0
From: nj, edison
Default

i would ck for leaks on the right downstream of the o2 first.
Reply
Old Mar 2, 2010 | 07:26 PM
  #7  
allan808's Avatar
Thread Starter
TECH Apprentice
iTrader: (3)
 
Joined: Sep 2009
Posts: 388
Likes: 0
Default

thanks guys!!
Reply




All times are GMT -5. The time now is 04:46 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE