[bruce]

this car is driving me nutz... its an 06 g6 with the 2.4 auto... i am now on my 2nd o2 sensor and again the check engine light (the dash light with the photo of the engine) is on again. the last o2 sensor i put in was the one after the cat and its part number is 15543 (bosch brand) the prob in the exhaust pipe is smaller than the stock one... now i am thinking its not the correct one.

any one got this problem or have the right part number for the first and second o2 sensor? and who had this problem but now its fixed?

 

[shawnner]

We have the same car - 2006 w/ L4 - and engine light problem. My mechanic has tried several times to repair and couldn't - then took to to the Pontiac dealer & still no repair.
_______________________________________________________

I took my car to the garage to have front wheel bearings replaced and check why the "check engine" light was on...Since my car was running perfectly, I thought maybe due to hitting 60k that it wanted routine maintenance.

Garage said my computer "quit communicating" so he re-programmed it. Since picking it up, my mileage and power are both down 25%...then the engine light went back on. Took it back, he reset it and cleaned the fuel line (rail?). But, same problem w/ mileage & power.

I have a 2006 G6 w/ 4 cylinder... used to get up to 34 @ 65mph down a flat highway and 26 mixed driving. Now 18 mpg in mixed driving.

 

[inspector2]

Other G6 owner w/ engine light on

Hi Guys,
I have about 74k on my G6. The engine light just came on. So far, only a slight drop in fuel efficiency has been noted. I've yet to have a code reader verify that it is a O2 sensor but, it was my first guess. I just did not know which one. I originally suspected the pre-cat one but, I've been told that it would be more likely the one after the cat. Question, did you guys reset the light via a code reader or by disconnecting the batt or what? I am not weathly enough to take the vehicle to a dealership, at this time.. so it is why I'm trying to fix it myself, with little investment as possible.

 

[shawnner]

After several trips to the dealer and the light continues to come back on (saying misfire code). My light has now gone out and has been out for a week - but still poor performance and poor mileage (25% reduction in both).

The dealer now says I have a bad cat conv and can be replaced under the 80k warranty for free. I doubt this will fix my problem, but at least it's free.

 

[geewhiz]

After several trips to the dealer and the light continues to come back on (saying misfire code). My light has now gone out and has been out for a week - but still poor performance and poor mileage (25% reduction in both).

The dealer now says I have a bad cat conv and can be replaced under the 80k warranty for free. I doubt this will fix my problem, but at least it's free.

It may help more than you know. Keep us up dated. I would like to know if this has helped.

 

[inspector2]

interesting

I understand that if a cat converter starts to get overheated and the guts start to melt, the exhaust will be restricted. Therefore power / efficiency will decrease. Let us know how it turns out. Sounds like maybe I should not mess around with the sensors quite yet. I quess the dealership is my only choice. Thanks very much

 

[shawnner]

thinkin it could be the cat conv

The more I think about how the engine "feels" and sounds when accelerating it could be a restricted cc. Hoping that helps & will post results here. Now, it's been on order for over a week with the dealer...so, just waiting. It does give me an excuse to ride the Harley pretty much everyday tho.

 

[wake2wake21]

iv got an 06 g6 2.4 auto (my post is the 06 g6 big problems) and iv been really trying to not take it to the dealer. iv been searching alot of forums and found this to be a reoccuring problem and this is EXACTLY EXACTLY what my car has done the previous six months or so, last month or so it progresses to stuttering at higher rpms and now resently it has no balls at all, so i floored it hoping to get another code to pop up or fix it, or blow that peice up. but no im only pulling a p0300 with is random multiple cly misfire. if u still got a warrany id run the holy piss outta it til it really f^cks it up like mine, and make them fix it, iv got my money on the table 40 bucks says this is a big problem with the 2.4 06 models search for this prob over the net with the lossing power and reduced fuel economy and see if ull take that bet lol
by the way i think it is computer controllled, like a sensor picking up false data and telling the comp the wrong info/tuning it wrong, hard to explain but my mechs when working on mine point to this.

 

[wake2wake21]

check post on 06 g6 big problems for update

by the way my cat was not clogged just malfuntioning so the o2 sensor was reading the wrong signals making bad adjustments, no warranty but new cat was free so im assuming a few cars have has this problem(when i mentioned bad running g6 they instantly said cat lol) they also told me it was clogged lol but babying it over to the dealer.... after 4 miles of barely gassing it at 20 it started to get better, alot better, but another 2 miles of flooring it it started getting less and less power and gradually acting up more. went back and forth a few times like this till i got there, by the way it wasnt like turning on a light switch power gain was gradual and loss was gradual it just depended on if i drove it 1/3 trottle or laid into it a bit

 

[inspector2]

check post on 06 g6 big problems for update

by the way my cat was not clogged just malfuntioning so the o2 sensor was reading the wrong signals making bad adjustments, no warranty but new cat was free so im assuming a few cars have has this problem(when i mentioned bad running g6 they instantly said cat lol) they also told me it was clogged lol but babying it over to the dealer.... after 4 miles of barely gassing it at 20 it started to get better, alot better, but another 2 miles of flooring it it started getting less and less power and gradually acting up more. went back and forth a few times like this till i got there, by the way it wasnt like turning on a light switch power gain was gradual and loss was gradual it just depended on if i drove it 1/3 trottle or laid into it a bit

wow, sounds like a real interesting drive to the dealer. hope all is good now. I diconnected my batt. and it reset the light. I'm waiting for it to come back on. I borrowed a obdII reader and it said "link failure", (this is before I disconnected the batt). Anyway, I was not about to replace the sensor without knowin for sure. BTW had some interesting brake problems too. I posted that on different post.

 

[shawnner]

The dealer replaced the Cat Convertor for free under their 80k warranty and BAMMM... I'm back in business! It worked... mileage back to 32 hwy / 28 mixed & runs strong - these L4's have the feel of a V6... happy again! Actually quite surprised....

Now, just to make it more confusing, I'm not sure what to believe. The dealer claimed that my first problems (read above) were the original problem with the car and the CC went bad in the process of those repairs... I think he wanted to be sure I'd pay for $600 worth of "other" repairs. My guess is that the CC was casing problems all along since nothing else they did made any difference.

 

[shawnner]

check post on 06 g6 big problems for update

by the way my cat was not clogged just malfuntioning so the o2 sensor was reading the wrong signals making bad adjustments, no warranty but new cat was free so im assuming a few cars have has this problem(when i mentioned bad running g6 they instantly said cat lol) they also told me it was clogged lol but babying it over to the dealer.... after 4 miles of barely gassing it at 20 it started to get better, alot better, but another 2 miles of flooring it it started getting less and less power and gradually acting up more. went back and forth a few times like this till i got there, by the way it wasnt like turning on a light switch power gain was gradual and loss was gradual it just depended on if i drove it 1/3 trottle or laid into it a bit

i just read this again & had to tell you...my problem felt very similar (almost ok when babied, but straight to heck when pushed evn a bit)

 

[davdes]

My new G6 Convertible 2008 does the same thing. Already 8 travels to dealer, 5000km done, and never ride more than 200km with check engine light off :-(.

It's my first GM...and the last one.

 

[Shield/Armour]

Hi All,
This is my first posting since purchasing a 2006 GTP.I love that vehicle.I recently got the oil changed with the wrong weighted oil and that may have tripped my check engine light.I am gonna have it checked regardless.Thanks for the tip about pulling the battery cable to reset.Getting ready for winter...see y'all out there.J

 

[Holtguy]

I have a 2008 G6 w/2.4L 4-cyl engine. At 7700 miles the check engine light came on. At the dealer they said the Evaporative Emission Canister was leaking. They replaced that, after a week the light hasn't come on. The only thing I noticed prior to the light coming on was my mileage dropped from about 22.5-23mpg (mostly city driving) to about 21.5mpg. So far the mileage seems a little better, but we'll see.

 

[inspector2]

maybe not the o2 sensor

After reading numerous posts, I was wondering if I should abandon the replacing of the O2 sensor. I was going to replace the post catalyst one,... reset the light and move on. It appears that there have been many different reasons (causes), for the light to come on, and based on the posts, the 02 sensor(s) has not been mentioned too often. I did try a OBD II device and it gave me a connection failure message.

 

[shawnner]

UPDATE on engine light...
The Cat Converter was replaced & the car has been running well... BUT NOW the check engine light has now come back on, very slight engine stutter from time to time, but only a slight difference in fuel economy. The lights goes on & off every 500 miles. I'm not going back til something falls off this thing... don't know what to think

 

[inspector2]

oh crap

UPDATE on engine light...
The Cat Converter was replaced & the car has been running well... BUT NOW the check engine light has now come back on, very slight engine stutter from time to time, but only a slight difference in fuel economy. The lights goes on & off every 500 miles. I'm not going back til something falls off this thing... don't know what to think

Oh crap. That is messed up. did you ever have any of the 02 sensors replaced? What was the readout on the OBD? Ya know..technology is great but when things start going awry..so much time and $$ is lost. I'd consider just ignoring the light but, here in California, when it's time for the smog check, it will poke me in the eye and my wallet once again. :3stooges:

 

[DTFK 562 G6]

Wtf!!!

2007 G6... My Check Engine Light Is Pissn Me Off Keeps Comin Bak I Have No Idea Wat The Hell Is Wrong With It But Ive Been Feeling A Big Loss In Power In My Ride And Was Woundering If U Guys Had Soome Advice Its At 74000 Mi Rite Now ???????

 

[markpetersonii]

I can take a look at it I have a code reader. I can look up the problem too my buddy has All Data.