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View Full Version : Need Wide Band A/F Gauge Advice



ProfessorB
04-28-2026, 07:23 AM
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I'm running a 427W with Holley 750 double pumper. I wanted a "stand alone" air/fuel meter to aid with tuning. I installed an analog-style (NOS brand) meter along with a Bosch LSU 4.9 O2 sensor which came with the kit. I am NOT impressed with the gauge. (Yes, it is installed correctly). It works sometimes....but not other times. Sometimes, under a steady load, rpm, and throttle position the needle will jump around quite a bit (for example, from back and forth from 13.0 to 19.0 rapidly).
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1) I've decided I want to change out the gauge and I am looking for recommendations for a better gauge. I would prefer analog style if possible as I find it easier to read at a glance while driving.
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2) I'm wondering about the plug connection for the Bosch 4.9 sensor. My question is: Is this connection a universal connection? If so, I would only need to buy a gauge and plug it in the the sensor I already have. This would lower my cost as I would not have to buy a complete kit. For some reason, I am thinking all Bosch 4.9 sensors have the same plug.
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Thanks for any help.

ggunter
04-28-2026, 07:50 AM
I too have the same engine set up as you do. I used a AEM afr gauge which gives both analog and digital read out.228614 I like its operation for tuning.

Dgc333
04-29-2026, 06:47 AM
FWIW, Engine Masters did a comparison of A/F gauges from the cheapest they could find to the most expensive and they all read the same.

David Ferguson
04-29-2026, 12:13 PM
The 4.9 sensors seem to all have the standard plug. The older 4.2 came in several different types. A good source for understanding the various bosch O2 sensors and their wiring is here:

https://www.wbo2.com/cable/lsuconns.htm

Wizbangdoodle
04-29-2026, 12:38 PM
Just ordered one yesterday. Should be here today. I'll report any findings when I have them.

ProfessorB
04-29-2026, 08:36 PM
FWIW, Engine Masters did a comparison of A/F gauges from the cheapest they could find to the most expensive and they all read the same.

Yeah, I'm familiar with the findings of the gauge comparison , which is why I bought a cheap gauge (NOS kit was only $200 with a Bosch 4.9 sensor). They didn't mention the NOS specifically and it just isn't working well.

ProfessorB
04-29-2026, 08:37 PM
Just ordered one yesterday. Should be here today. I'll report any findings when I have them.

I'm curious about which one you ordered?

cv2065
04-29-2026, 09:47 PM
I'm looking at this one. BT and goes to your phone.

https://pe-ltd.com/product/wideband/