1991 Honda Accord EX Wagon Flashing Sport Light

Hey, all!
I recently bought a Honda Accord Wagon with 311K miles. It’s needed a few things to get it running again but so far, it’s all been sensors and just needed some fresh gas from sitting for a year. I’ve been driving it daily otherwise with no complaints. Thing’s a beast as far as high mileage 4 bangers go! My issue though is; There’s a “Sport Mode” indicator light on the dash (AKA – The ‘S’ Light) that keeps flashing. I’ve checked the codes and there aren’t any. When I got it there was a CEL for the ECT sensor and that’s since been taken care of and is off. I’ve done quite a bit of researching on this and found that there are typically two common repairs for this.
1: Speed Sensor replacement
I’ve dug through almost every forum on this particular repair method and found it to be the MOST common with some differing side affects. Some say the speedometer stopped working some say that it stops shift out of 1st gear or has issues down shifting. For me – The only issues i’ve had is that it shifts a little hard and lags on the up-shift. All of them say the “S Light” is flashing. The speedometor is only 5mph off but it works and doesn’t do anything weird like some others have reported.

2: TCU Replacement/ Repair
This particular repair I would like to avoid if possible. I bought this car to be a cheap beater and though I’ve come to absolutely love it, I don’t want to spend a ton of money on it. I’ve found a few repaired TCU’s for reasonable prices, but just don’t want to spend upwards of $250 on a car that I only spent $500 on.

Why I’m here:
I’ve already replaced the speed sensor and it still is flashing and lags on the up-shift and has a kick to it. Could there be any other possible explanation? Is there a way to pull codes directly from the TCU?