well, just like the title says.....I have had my car tuned by a friend, but not certain that he was perfect with his tune... I know I should start there, but wanted to know if anyone else has ever encountered this. I think my mods are in my sig, but Ill put em here just in case.

95z, A4; LT's, 1.6rr's, Elec. WP, !CAT, !EGR, TB Bypass, 3600 stall, 30lb injectors, bored .030", forged pistons & rods, balanced assembly, milled heads w/ 3 angle valve job, Walbro fuel pump, nx wet, custom cam 525/525=238/238 (which is mildly wilder than a hotcam), Im sure im missing some stuff, but this will give you the gyst of it.

I only drive it like once a month, so it's not my everday driver.....but thank God for unlimited warranties, as I would go broke on these O2 sensors. BTW, gas mileage sux too. 150 miles per tank with a little heavy foot.

Billy D.

 

Do you have Leaded gasoline in your car? Did you add any additive to your gasoline that may contain Lead? There is one "pass smog" item for sale at the autoparts store and sitting right next to the other "pass smog" item and one is for unleaded gasoline the other one I think its for diesel.... did you pick up the wrong one?

Bottom line.... you need to find out what is happening to the O2's. Are they getting fouled up with carbon? or are they getting contaminated?

If they are getting contaminated.... do you have a small leak of Coolant into your exhaust? A cracked cylinder will will sip coolant or maybe a very small coolant leak by the Head Gaskets (aka blown head gasket).


I know Lead in the gas, Carbon fouling and Coolant will Kill the O2's fer sure.... I hope that gives you a good starting point.

Marvin

 

I'm in your boat too. My sensors crap out after about 2-3 weeks of driving as I keep getting the "slow responce" code. I know I have never used any sort of leaded additive or gas. I am also pretty sure that I do not have a coolant leak, but how could I tell? I am not low on coolant or anything.

 

I dont think I have any headgasket problems, as this is a freshly built motor, and dont believe that I have a leaky cylinder wall either. The spent O2's smell like pure fuel. My neighbor is a mechanic at the local chevy dealer, but I hate bugging him after he comes home to "relax", not "work". It's really not that big of a deal to change them, Im just sure that the place im getting them from is tired of seeing me every third time I drive my car. Ill just put the stock injectors back in, and see what happens. Send off my compy, have it redone, and put the 30's back in.. I have to have it done anyway for my stall.

Billy D.

 

Make sure there are no exhaust leaks.

 

ok fianly its happening to someone else. i have this same problem. i got the an 02 evey 2 months or so

 

As far as exhaust leaks go, i have a borla catback and where 2 sections of the pipe slip together there is no clamp. One of my O2 sensors just went, would the missing clamp be significant enough to cause that problem

thanks

 

an exhaust leak before the O2's would cause that bank to run rich. check your manifold to head area for leaks and you might want to check the AIR valve that is on top of the manifold, if it is allowing exhaust back up into the hose it is the same as a leak anywhere else. basically just open the hood when the car is running and feel around the manifolds and smell around to see if you smell exhaust gasses in the engine bay.

 

How much do the 02's cost?

 

45-65 bucks.....but if youre smart, youll make sure that you have a lifetime warranty the first time

Billy D.

 

It would have to be before the O2 sensors, or a few inches after at most.

 

2 things come to mind:

1-did you use non-sensor freindly gasket sealer?

2-It must be in the tuning. What's the inj. pulse width like? Are you seeing black clouds of smoke? What's the blm's look like?

 

I know for instance on my header install I used Permatex copper RTV, but it says it is sensor safe. I did use it on the header gasket, but since it is sensor safe, when it burns it shouldn't mess up my sensors right?

On the highway, my BLM's tend to be in the 110-115 range. I know this means the computer is correting a rich condition. Could this be due to my sensors going out, hence giving the slow responce code?

I didn't mean to hijack the thread but we are both having the exact same problem..

 

Let us know.

 

Well I know that my sensors are bad because on both of them I get a "slow responce" code which basically means they are on their way out from contamination or something else. My richness may very well be because of bad plugs/wires, but it doesn't run that rough at all. The tuning is stock as well as the fuel injectors. Only thing MAY be an exhaust leak, but I have not found any that are before the sensors.