1988 Acura Legend Coupe, The tachometer stopped.

Scan for codes and check fuelpressure first

Code 1 means an oxygen sensor but it doesn't say front or back here is the way to check it if you are mechanically inclined. You may need aharness adapter to do this though
Press Ctrl+F to find exact text

CODESÂ 1Â &Â 2 Â O2Â SENSOR

1. Turn ignition off and reset ECU. Remove alternator sense fuse in under hood relay box for 10 seconds to reset ECU. Sta
pressure. See FUEL INJECTION article. Repair fuel system if not within specification. If fuel pressure is within specifi
2. Bring engine to operating temperature (cooling fan on). Hold engine speed at 1500 RPM for 15 minutes,  without closingÂ
this time. Check if "CHECK ENGINE" light is on and if LED is indicating Code 1 or Code 2. If not on,  problem is interm
again.
3. If light is on,  disconnect indicated oxygen sensor connector. Attach voltmeter to vehicle ground and connector. With eng
temperature,  momentarily open throttle wide open,  then close throttle.
4. Voltage at wide open throttle should be greater thanÂ.6 volt,  and less thanÂ.4 volt at full closed throttle. If not within sp
sensor. If voltage is within specification,  proceed to next step.
5. Turn engine off and attach system checker harness between ECU and ECU connector. Using a voltmeter,  connect negative terminal A18
6. For front oxygen sensor,  attach positive voltmeter lead to connector terminal C12 and C10 for rear oxygen sensor. See
7. Start engine and warm to operating temperature. Momentarily open throttle wide open,  then close throttle. Voltage at wi
greater thanÂ.6 volt and less thanÂ.4 volt at full closed throttle. If not within specification,  repair wire between ECU and
specification,  substitute a known good ECU. If condition is rectified,  replace original ECU.

Try cleaning the battery terminal ens first for heater/lights etc. And no the valve cover gasket don't effect them.

If the trans is taking off in 2nd gear thre is a good possibility the trans is bad due to clutch/seal wear. That's probably whyyour s3 light is blinking.

Here is away to check it though it says 1990 but it's the same for your year.
"S3" Indicator Light Is ON Steady Whenever Ignition Is ON (1990 L5)

1. Turn ignition switch OFF. Disconnect 26 Pin and 22 Pin connectors from control unit. Check for continuity between B13Â
ground.
2. If there is continuity,  disconnect 2 Pin connector from "S4" switch. Check for continuity between B13 (Green ) and body g
continuity,  repair short in Green wire between B13 terminal and "S4" switch. If there is no continuity,  replace "S4" switc

NOTE: For additional electrical circuit information,  see WIRING DIAGRAMSÂ.

3. If there is no continuity,  turn ignition switch ON and measure voltage between A23 (Red ) terminal and body ground. If th
ATCU. If there is voltage,  measure voltage between Red wire at gauge assembly to body ground. If there is no voltage,  rep
indicator. If there is voltage,  repair short to power source on Red wire between A23 terminal and gauge assembly.

It could be anything either the front or rear O2 sensor or a short in the wire or bad connection at pcm. I have no other suggestions.