Check Engine and Reduced Power Lights

Hi,

I own a 2003 Isuzu Rodeo, V6 3.2L My check engine light has been going on and off sporadically over the last two weeks. This morning, I got in my car and the Reduced Power Light was on and the car would not go over 10mph. I went in the house, let it sit for an hour and started again with no problems. I took it to Advanced Auto and the following codes were detected
p1290
p1340
p1311
p1312
I have seen other threads with this problem, but did not see a solution. Many people were told many things by mechanics to not fix the problem. I do not have money to try all of the things recommended. Can someone help? I have heard everything from bad gas to a bad wire harness.

1) Could water from rain, or a car wash be a factor?
2) How about heat?

There's somthing causing your ignition timing tobe @ fault triggering the Limp mode.

Water can short the ignition signals out, clean connections with CRC electric cleaner, and use dielectric grease for protection.

Heat to a bad coil, spark plug wire could cause more resistance.
Heat to a bad PCU, ICM could cause less resistance.

1) Could water from rain, or a car wash be a factor?
2) How about heat?

There's somthing causing your ignition timing tobe @ fault triggering the Limp mode.

Water can short the ignition signals out, clean connections with CRC electric cleaner, and use dielectric grease for protection.

Heat to a bad coil, spark plug wire could cause more resistance.
Heat to a bad PCU, ICM could cause less resistance.

Heat may be a factor. It has been extremely hot here this summer. And I have noticed the CEL seems to come on if I have the car running for a lengthy time when it is really hot. But sometimes it is still on the next morning and sometimes not. I did however, stop and fill up at a cheapo gas station on Friday. Car was fine all day Friday. Saturday it was not driven, Sunday car was fine, and this happened Monday morning after parked in garage all night.