LS4 Performance Grand Prix GXP | Monte Carlo SS | Impala SS | LaCrosse Super

Grand Prix GXP

Thread Tools
 
Search this Thread
 
Old Nov 19, 2023 | 05:18 PM
  #1  
DanMurphy's Avatar
Thread Starter
Teching In
 
Joined: Nov 2023
Posts: 2
Likes: 0
Default Grand Prix GXP

Code P0135

replaced O2 sensor twice, to no luck incase first was defective. Replaced harness plug, to no luck. Check power voltage 13v. Ohmed out wires to 6” from pcm… all to no luck at 0.1 ohms on all 3.

what could be causing the p0135 sensor 1 heater malfunction besides the o2 sensor and wiring?
Reply
Old Nov 27, 2023 | 03:52 PM
  #2  
MoneypitLS4's Avatar
Teching In
 
Joined: Nov 2023
Posts: 2
Likes: 1
Default

Could be a fuse or exhaust leak prior to sensor
Reply
Old Nov 27, 2023 | 04:38 PM
  #3  
DanMurphy's Avatar
Thread Starter
Teching In
 
Joined: Nov 2023
Posts: 2
Likes: 0
Default

Originally Posted by MoneypitLS4
Could be a fuse or exhaust leak prior to sensor
I found and fixed issue.

Ohmed out all 3 wires to pcm. 0 ohms, so the other possibility is wire sheathing poor. So yes, found





the wires going through main wire harness are catching magnetic fields.

pulled the wires out of harness, completely entangled, so had to cut and splice back in. Wrapped in electrical tape once over. Good enough to stop the magnetic fields from other wires in harness. Separated alternator power wire and O2 sensor wires into new loom.

going back to loom in the main harness once that arrives.
Reply
Old Feb 14, 2024 | 03:42 PM
  #4  
MoneypitLS4's Avatar
Teching In
 
Joined: Nov 2023
Posts: 2
Likes: 1
Default

Glad you found your issue. Seems like on these cars the wires fail more than the sensors/switches do. They're all just about a 1/2" too short, too stiff, too many together, not enough gauge for the current, just all around poor quality wiring. Guess that's why they call it a GM parts bin car. I also had to break out all the wiring like you did, except mainly to make room around the truck intake swap (Which does fit BTW). I ditched the original battery terminals and did individual direct run 2/0 from battery to starter, to fuse box, and one to alternator. Then 2/0 ground to motor and one to chassis. The positive battery terminal finally stopped corroding, but the parasitic draw is still there. (That's the radio/BCM)
Reply




All times are GMT -5. The time now is 03:42 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
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-4
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-5
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-6
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-7
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-8
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-9
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