Canadian Mid East Nunavut, Manitoba, and Ontario

Hello, also CAT delete re-flash computer?

Thread Tools
 
Search this Thread
 
Old Mar 15, 2023 | 09:32 AM
  #1  
hhr_canuck's Avatar
Thread Starter
 
Joined: 03-15-2023
Posts: 3
From: gta
Hello, also CAT delete re-flash computer?

Hello all, my first post.
2007 HHR LS 2.2 Auto 4 door.
I bought her new in 2007 for the Wife as a push present, was the only car that had a trunk that fit the double baby stroller.
If you are married, you'll understand these next statements:
Bought wife a Chevy Volt now I get the old car as is always the case.
Been maintaining it all this time, never an issue. However been a few years since I drove it, took it for a spin and the steering is terrible and the shocks are shot.
So forget putting back on the road, I'm going to be putting it on the ice race track for next winter, off road application.
The babies it once carried will be 16 next winter and want to learn to drive it on the ice course.
I have deleted the CAT, and then the code.
Would anyone here know if it's possible to get the computer reprogrammed to ignore the volt difference between the two O2 sensors?
I would still like to keep the computer (not use MSExtra as in my Chevettes) and get notice of other engine related issues, but with that orange engine light on all the time you won't know if there are other issues.

Thanks.

Old Mar 15, 2023 | 09:55 AM
  #2  
Oldblue's Avatar
Administrator
 
Joined: 10-13-2011
Posts: 40,082
From: Welland,Ont Canada
Welcome to the site, I don’t see any advantage to deleting the cat, I have see improvements with a 2.4 cat, these are mandrel bent and sound much better as the 2.2 likes to breathe! I added a K&N FIPK and this cat

https://mufflerexpress.ca/products/c...rter-2005-2007
Old Mar 15, 2023 | 11:09 AM
  #3  
donbrew's Avatar
Moderator
 
Joined: 01-23-2009
Posts: 26,532
From: Fredericksburg,VA
The answer to the question is: NO, it is not legal to do that. I guess that if you unregister the car and remove the tags you might be able to convince somebody it is "off road only" and maybe your locality has that sort of classification.
When there is a P0420 code the computer runs in open loop so, any advantage in deleting the cat is overcome by no feedback from sensors. Might as well just yank the computer and put a carburetor and distributor on it.
Steering is pretty easy to fix; get 2 new LCAs and struts, about $500 in parts.
Old Mar 15, 2023 | 12:14 PM
  #4  
lazaino's Avatar
Senior Member
 
Joined: 03-08-2008
Posts: 303
From: los angeles
In the past you could buy O2 sims which plugged onto the rear O2 plug and set a signal to the ECM that made it happy. If you do electronics it was something like a 1 or 2 hz square wave toggling between above and below stoich. The ECMs back when you could buy those were not very critical of that input. After the EPA took them off the market I was tasked with making one, I did but it was never produced. I think the original might have used a 555, I use a 6 pin microprocessor.
Old Mar 15, 2023 | 12:29 PM
  #5  
hhr_canuck's Avatar
Thread Starter
 
Joined: 03-15-2023
Posts: 3
From: gta
Thanks for some pertinent information lazaino. You gave me some important information, it is the upstream O2 that is giving the feedback for AFR.
Do you know if the downstream O2 needs a lower or higher voltage than the upstream?
I have been driving electric cars for the past few years and am a bit rusty.

I guess the previous two posters did not read my message in full that this is an off road application.
Why would I replace a clogged CAT for an off road use? I digress.
It appears donbrew is a bot or works for Al Gore.
They should be googling "what is MSExtra".

Old Mar 15, 2023 | 12:54 PM
  #6  
lazaino's Avatar
Senior Member
 
Joined: 03-08-2008
Posts: 303
From: los angeles
As I understand it, the sensor after the cat just needs to respond over the same range as the front sensor, but much slower as the cat evens out the AFR.
Old Mar 15, 2023 | 12:55 PM
  #7  
Oldblue's Avatar
Administrator
 
Joined: 10-13-2011
Posts: 40,082
From: Welland,Ont Canada
First off, Donbrew is our Technical Director, and I’m the site’s Administrator,

You would replace the cat to get the computer to work and give you optimum fuel efficiency, I did read your post and I do understand what you are doing with the car, Ice track driving, does that sanctioning body have a rule book? Do they allow cat delete? You need to understand, we have years of experience with these HHR’s , there are tuner companies out there , but they cost much more then the Cat I linked to .
Old Mar 15, 2023 | 01:20 PM
  #8  
hhr_canuck's Avatar
Thread Starter
 
Joined: 03-15-2023
Posts: 3
From: gta
"First off, Donbrew is our Technical Director, and I’m the site’s Administrator,"

I see.
As the ones responsible for the forum, you are covering your behinds and don't want to be responsible for any illegal activities hence your post.
Just put a disclaimer next time and try to be a bit more professional.

So, original question was "can the computer be reprogrammed to ignore the 2nd O2 sensor.
So far, nobody knows, but it's possible to simulate the 2nd O2 sensor.
My co-worker an Electrical Eng just visited, he's already made his own simulator for his GM, so looks like he'll build me one too.




Old Mar 15, 2023 | 02:05 PM
  #9  
greg8453's Avatar
Senior Member
 
Joined: 03-29-2022
Posts: 1,241
From: Davison MI
Originally Posted by hhr_canuck
"First off, Donbrew is our Technical Director, and I’m the site’s Administrator,"

I see.
As the ones responsible for the forum, you are covering your behinds and don't want to be responsible for any illegal activities hence your post.
Just put a disclaimer next time and try to be a bit more professional.

So, original question was "can the computer be reprogrammed to ignore the 2nd O2 sensor. NO
So far, nobody knows, but it's possible to simulate the 2nd O2 sensor. They sell these. Do you have inspections because none will pass.
My co-worker an Electrical Eng just visited, he's already made his own simulator for his GM, so looks like he'll build me one too.
Why do you not want to fix it?
Old Mar 15, 2023 | 04:18 PM
  #10  
firemangeorge's Avatar
Platinum Member
 
Joined: 12-06-2009
Posts: 11,721
From: Alabama
Ice racing ? Wow. Didn’t know they had redneck sports up in Canada. 😂

My opinion. This is the wrong forum for you. Find a racing, off-road or hotrod type forum.



All times are GMT -5. The time now is 11:24 AM.