Lack of power and code P1890

Did you ever get a chance to verify this code number? I do not see it at all.

Does the transmission work correctly? Are you having an issue with shifting?

https://www.2carpros.com/articles/automatic-transmission-problems

This code is for transmission shifting errors.

You will need an advanced scan tool to check this code. I posted the description below for you to view.

Roy

Problem in Shift Control System

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.

1. Clear the DTC with the HDS.
2. Test-drive the vehicle for several minutes in D through all five gears, then slow down to a stop.
3. Turn the ignition switch to LOCK (0), and repeat the test-drive in step 2.
4. Check for other DTCs indicated simultaneous with DTC P1780.

NOTE: DTC P1780 means there is one or more A/T DTCs about the shift control system.

Are there other DTCs?

YES - Troubleshoot the problem indicated by the DTC.

NO - Go to step 5.

5. Update the A/T software in the PCM if it does not have the latest software, or substitute a known-good PCM.
6. Test-drive the vehicle for several minutes in D through all five gears, then slow down to a stop.
7. Turn the ignition switch to LOCK (0), and repeat the test-drive in step 6.
8. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS.

Is DTC P 1780 indicated?

YES - If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.

NO - Go to step 9.

9. Monitor the OBD status for P1780 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail.

Does the HDS indicate PASSED?

YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other DTCs were indicated on step 8, go to the indicated DTC's troubleshooting.

NO - Check for poor connections and loose terminals at the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 6 and recheck.

Welcome to 2CarPros.

Is the check engine light on and staying on or flashing when the engine is running?

https://www.2carpros.com/articles/check-engine-light-top-ten-reasons

If it stays on, has the computer been scanned to retrieve diagnostic trouble codes?

Has the fuel pressure been tested or has anyone checked for a partial plugging of the catalytic converter? If not, have that done.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know.

Joe

If there are no codes, then it becomes a test procedure. Have you checked fuel pressure? Have you checked to see if anything is plugging the catalytic converter?

Let me know.

Joe

Scan for codes and check fuel pressure first. If ok check for timing belt jump or broken

Have you tried removing a pre catalytic converter oxygen sensor to see if it changes? The exhaust may appear to be good, but internally, there could be issues.