best o2 sensors??

**Ortiz11b** · 09-03-2011, 12:59 PM

I haven't done lt headers yet,, but plan to this fall... my car is running a little rich and looking to change my o2 sensors. So would like to get the right o2 sensors so when i do my long tubes i wont have to buy them again,,, i searched the topic and found people recommending the Denso 234-4025 or the bosch 13111. My question is do i need 2 of the same part # or are they different part numbers on each side??? for the price and what i read is the denso is favored... and cheaper.. do i just need 2x part # 234-4025.... thanks

**Knight** · 09-03-2011, 01:28 PM

Yep. Two of the same.

**pajeff02** · 09-03-2011, 02:06 PM

The Bosch 13111 sensors are a good choice as they come with a nice long wire harness. When you upgrade to LT's, you won't need harness extensions as the Bosch units will go the extra distance needed.

**Ortiz11b** · 09-03-2011, 02:22 PM

Are the Denso not extended also?

**pajeff02** · 09-03-2011, 04:46 PM

I have no idea.

**redbird555** · 09-03-2011, 08:08 PM

Some people have problems with bosch sensors not working correctly with their cars... Me being one of them, my new bosch sensors went out within a few thousand miles and switched VERY slowly. The denso's are oem so why not go with them? If you get denso part no. 234-4617 it will be the correct length for lt's. I have personally watched the 2 sensors switch side by side on my car (the bosch was 2 months old) and the denso switched much faster and they are still going strong almost 2 years later.

**pajeff02** · 09-04-2011, 03:28 AM

Over two years with our Bosch sensors and no issues at all.

**redbird555** · 09-04-2011, 04:32 AM

Not saying they dont I've heard of some people being fine with them and others the car wont even run. I had issues to I switched and the general consensus is that there are better sensors than bosch out there for the same money like ntk or denso. Like I said though I can vouch with my own eyes seeing the densos switch much faster than the bosches

**Knight** · 09-04-2011, 04:37 AM

Originally Posted by pajeff02

Over two years with our Bosch sensors and no issues at all.

Same here.

**Ortiz11b** · 09-04-2011, 07:45 AM

Ok i keep hearing mixed reviews on both bosch and denso,,, let me ask you all this...

Ones running Bosch where did you buy them and what year is you car??
Ones running Denso where did you buy them and what year is you car??

I know that there are small differences in the ecm from the 98-02 ranges... im just wondering why some people love one brand and hate another....lol there's got be some science behind this... or is it just some people see Bosch=Ford??? lol
Thanks for all the input,,,

**Knight** · 09-04-2011, 08:31 AM

My car is a '99, and I think I shopped them online for the best price. It's been a few years, so I don't remember exactly where I ordered them from. Never had an issue though.

**pajeff02** · 09-04-2011, 08:58 AM

'02 Trans Am and bought them at the local Autozone.

**Cutlass** · 09-04-2011, 01:07 PM

My car is a '99 and I bought my Bosch sensors at NAPA. Never had a problem with them.
The Bosch and Denso sensors should both work just fine. If you go the parts store, ask for rear O2 sensors for a 2000 Corvette. those are the sensors with the long harness and the correct connector for an F-body. From there, they'll ask you what brand you want.

**My00Z28** · 09-04-2011, 01:27 PM

well i have bosch's in my 2000 Z28 with LT's and im not having much luck my bank 2 sensor, it keeps tripping. i watched the live data and it would take 5 seconds to switch when bank 1 was switching instantly!

**Firebirdjones** · 09-04-2011, 01:38 PM

I run Bosch 13111's in both of my 4th gens with long tubes and have never had an issue. I did however have issues with the GM sensors on one of the cars, kept setting heater codes on cold days. Stopped when I switched to bosch sensors.

**pajeff02** · 09-04-2011, 02:13 PM

Cutlass and FBJ don't need told this, but FWIW the O2 sensors need to come up to temp to operate properly and have a heating element that helps achieve this. Also, upon cold startup, our cars run in open loop and do not accept feedback from the O2 senders to adjust fueling. Once the PCM switches over to closed loop it them looks to the sensor data and adjusts fueling accordingly. Obviously, there is a lot more going on, but this gives a basic idea of how they work.

**Firebirdjones** · 09-04-2011, 02:48 PM

Right on Jeff, and the stock 02's are mounted pretty close to the engine with stock manifolds, which helps the heating issue.
Going to longtubes moves the 02's so far down stream that sometimes warmup issues raise their ugly heads and you get heater codes tripping

That was the problem I had.

They will all tend to get lazy with age and mileage and have slow switching issues. Which is why it's recommended they be changed as regular maintanance every 50-60,000 miles or so no matter what brand you choose.

**My00Z28** · 09-04-2011, 02:51 PM

Originally Posted by Firebirdjones

Right on Jeff, and the stock 02's are mounted pretty close to the engine with stock manifolds, which helps the heating issue.
Going to longtubes moves the 02's so far down stream that sometimes warmup issues raise their ugly heads and you get heater codes tripping

That was the problem I had.

They will all tend to get lazy with age and mileage and have slow switching issues. Which is why it's recommended they be changed as regular maintanance every 50-60,000 miles or so no matter what brand you choose.

how does every 5,000 sound cause thats what im at and having random problems again car runs fine for a bit then throws a code, i clear the code then it runs fine, then 3000-5000 miles latter code trips again

**Firebirdjones** · 09-04-2011, 02:55 PM

Originally Posted by My00Z28

how does every 5,000 sound cause thats what im at and having random problems again car runs fine for a bit then throws a code, i clear the code then it runs fine, then 3000-5000 miles latter code trips again

What code are you getting? If you are having issues after 5,000 miles, it might be a faulty sensor, and they should have a replacement warranty on them. I know my Bosch sensors I bought locally were covered for a short time (just can't remember how long) But if there were a problem it would usually happen pretty quick anyway, such as your case.

**My00Z28** · 09-04-2011, 03:03 PM

it was something bank 2 sensor 1 low voltage bla bla bla p0151 or something like that the sensors were new at the beginning of the year B2S1 was then replaced under warranty about a 1-2 months ago and same issues! bosch 13111's