Hi all,
Just replaced Bosch o2 sensors with Denso to help clear the heater code. The heater code is gone but now the car runs like absolute crap unless I'm hard on the gas. The idle surges come to a stop light and anything less the 1/3 throttle the motor surges and feel like it's missing firing with a strong fuel smell. Any ideas?

 

Heater code is gone...any other codes? Sounds a little like a vacuum leak or a plug wire loose or off. Check the plug wires also to the coil packs. Get back to us with if there are any other codes.

 

Did you break one of the wires when installing the O2 sensor or did you get a damaged one by chance?

Also, did you pull the battery lead to reset the fuel trims when you swapped them out so it could relearn? If not, I'd start by doing that. Make sure to leave it off for 30 minutes or so to make sure the computer resets.

 

Positive you didn't switch left to right...?

 

No other codes and double checked left/right and all set there. I pulled the battery cables and will try that in a little while. Didn't see any obvious vacuum leaks but def. can't rule that out that.

 

...Crap !!, didn't want to read this, since I'm getting ready to replace upstream 02 sensors myself to eliminate the same code !!...
BTW, 01badvette...Please do a follow up reply on this issue if you find out what's causing the problem !!...

 

No vacuum leaks I can find I double checked all the lines, no codes, it runs fine cold, as soon as it get hot,it all goes to hell like I said before. May have to swap the old O2 sensors back on may have possible gotten a damaged/defective one but y no codes?

 

I would double check all the connections and wires leading up to the sensors. If all appears fine, try swapping in another set of sensors that are known to be good to see if the problem continues. If the car ran fine until these were installed, it sounds like it should be isolated to the new sensors.

 

Car was running perfect before these new sensors except for the damn O2 heater code. I'm half tempted to swap the connections from side to side just to see if it makes a difference. And I have two sets of est. good O2 sensors (Bosch) I'm gonna swap it's just a pain with the long tubes on.

 

BC

 

I hope this is constructive, as my repair skills are low, and my wind is long.

I had my newly purchased 03 in the shop for a clutch. I had seen an old Hot Rod TV show where they replaced the lazy old sensors with new and then showed the improved wave form , before and after. My repair skills don't go far beyond watching tv, so I hesitate to post a lot of basic stuff.

While my car was apart, I suggested to the service writer that he replace the sensors. K and D corvettes was the shop , a busy high production place with a gang of work stations.

I was surprised when the service writer turned the suggestion down. Few people leave money on the table. He was concerned about putting an unknown part into the car. I assumed a new part would be a known item, but let his judgment and experience prevail.

He runs a busy shop, mostly older stuff , and when you pay the bill, he might proudly show you his show horse pictures, which reinforced , to me ,his judgement and ability to generate income, that stuff isn't cheap.

From his concern about untested sensors, I got the impression these parts are suspect, or it could be they are using cheap sensors to cut costs. I doubt it, any returns for repair adjustments blows the profits.

I am hoping the electrical reset will fix this sensor issue. I still want my sensors optimized, and await the results, planing a DIY. At one time I assumed it would be like changing a light bulb, just like on TV.

 

Looks like one of the "new" sensors was bad.

 

Not everything is perfect out of the box...

 

...Please let us know if replacing that one Denso sensor was the problem and the results of how your car is running after being installed. I too also have a pair of new Denso sensors ready to install.. !!....

 

Glad to hear you got it figured out

 

Wasn't the sensor

 

That'll do it. Did it get up against the exhaust?

 

Yea the LT headers there's some pinch spots. When I moved it around to install the new sensors must have finally broke it thru

 

...Glad to see that you found the problem, now, is the car running normal !!...

 

Car is back to running normal, a quick hour job turned into a 2 day headache but it happens sometimes.