Ever since I bought my Autometer 3579 air/fuel gauge via Summit, it has not worked correctly. Instead of starting the engine and having it read within seconds as the sensor warms up, the ONLY way to get it to read was to turn on the key, wait about 30 seconds for the sensor heater, THEN start the engine. (Which is exactly what the instructions tell you not to do). It would then work until key-off. With a restart and the engine hot, it wouldn't even work half the time if I waited.

Yes, I tried another expensive wideband sensor and it did the same thing exactly. The wiring and voltages are correct at the gauge terminals.

So I sent it back for repair to Autometer who signed for it on Sep. 28th. Didn't hear anything, so I just called and got "Max" on the phone. Overall he was rather rude.

He informed me that they checked it in yesterday (a full 8 days after receiving it from FedEx!) and were unable to reproduce the problem. Their solution is to sell me a brand-new replacement gauge for $122. When I protested, he repeated himself and gave me the choice of getting it back unrepaired for free. Because it's outside the 1 year warranty, he could care less.

I bent over and paid the $122 - but the next time I buy an AFR meter it will NOT be one of theirs. Now let's see if the new one works according to the manual...
YMMV.