Ok when I got my truck in 2010, a month later I installed LTs and high-flo cats from Dynatech. I had it tuned. Three days later the "SES" light came on. Went to autozone and it read front O2 sensor blah blah blah. Smells a like gasoline at idle all the time. I called the tuner and he said he may need to turn the front o2 sensors off. I've read here and there and most folks don't recommend that. I read somewhere else thou that switching to rear C5 O2 sensors would correct the problem. Anyone ever heard of such a thing? Call another local and advertised tuner and they recommended moving the front O2 sensors 6-8 inches because they my not be getting up to operating temp but, without it being on the laptop how would they know it's right on? Turning off the front O2 sensors has been my only solution? Is running open loop safe? So what can I do to fix this issue for good? Thanks Daniel

 

Anybody have any clues? I'm sure I'm not the only who has had this issue.

 

You would need to turn the rears off not the front. Yes switching to the vette ones helps, as I believe they are pre heated. I get the same issue, the truck will load up some times, because the front 02's will not get in the op zone fast enough. A easy try would be to wrap the area with some heat wrap around the 02 section and slightly infront of it to keep the heat in.

 

Yes of course the rears are turned off not the fronts. The tuner had mentioned he'd probably needed to turn the fronts off too. I'm not a tuner but know enough to know that would be worse. I'll try the wrapping and if it works I'll switch to the vette ones or should I get the vette ones anyways? Thanks for the imput. I really appreciate it.

 

I would have them turned off( rears). I wasn't sure if you were insinuating that you were going to do that with the front or not. I do not think the engine would run remotely close with the fronts off unless you were SD tuned.

 

Turn off rear O2's
Your front O2's are switching slow due to cooler running exhaust. This also prematurely burns up the O2's heating element. It can be tuned out but you'll eventually need to upgrade your front O2's to corvette rears.

 

If you are not running speed density, then you need those front o2's, can't tune them out. BUT your tuner can just turn that error code (and others) off. But you won't know when they do die besides your gas mileage goes to ****.

Other posters are right, the o2's are not at operating temp.

I believe the collector on the dynatech's is where they have them. That's as close as you can get to the head on that setup. So wrap the headers or change the front o2's to a hotter o2 ,which is not a 100% guaranteed alternative. (old trick of using rear vette sensors). Plenty of discussions in here on the topic. Those sensor heating elements will die sooner and they will constantly bug you until you help them get some of the heat they lost in you going to headers.

At the end of the day you are running richer (wasting gas). Failsafe. Richer is safer than leaner.

 

I would be alittle skeptical about my tuner if his first recommendation was to turn off the front 02's.

 

Yeah I was skeptical with him after his suggestion that's why I never went back. I called Dynatech to get some help but the guy I spoke with didn't know? I left someone a message in another department but never got a call back. I will change to the Vette rear O2 sensors then. Thanks for all your advice guys. My mileage has been 14.6-15.2 combined. Not too bad I think. Better than my LS1 ever did and LQ4 ECSB too. I didn't do the headers for mileage, I did them to have fun with my truck. Thanks again for all your help. Daniel

 

Oh, by the way, Tiffo60 what size drop is that?