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I have been fooling with this for awhile and thought you guys could come up with some suggestions on the next step.
-98 Chevy Astro Van. 4.3 Liter Auto. Was a California car before I got it with 163,000 miles two years ago.
-It now has 190,000 Miles.
-Check Engine Light (CEL) came on and eng started to miss at steady highway speeds. Under load eng ran fine.
-Had the code read at a parts house and they came back vacuum leak left bank and bad vacuum left bank.
-After a lot of searching found a bad hose going through the firewall under the A/C. The source for this hose was on the left side of the intake. Replaced this hose with no change to eng performance or check eng light. Checked all the sensors per the Maintenance Manual and all checked good.
-Took it back to parts house and got codes for Coolant Temp. Sensor input voltage low. No vacuum leak showed up. Replaced the Temp Sensor and Temp Sensor wiring for lack of anything better to do. At this point I got a OBDII code reader and the only code was P0300 (Random/Multiple Cyl. Misfire Detected).
-Eng. Performance had gone from bad miss at steady speeds to missing at all speeds and under any load. Changed Spark Plugs and Wires with no change. Changed Distributor Cap and ran like new but CEL stayed on.
-At this point life kind of got in the way and since it was running good it got put on the back burner. After about 5,000 miles it started missing again so I read the codes and all that showed up was the P0300. Replaced the Distributor Cap and it ran like new again. Light was still on.
-Ran fine for about 5-6,000 miles then the miss came back. Life had slowed down so I got into some heavy searching, well I reread the manual for the scanner and realized it was telling me that there was several sensors not working. Found a blown fuse under the hood and found the right 02 Sensor shorted to ground. Replaced that and got a P0422 code (Main Catalyst Efficiency Below Threshold). And of course the P0300. The P0422 did not surprise me since it had been missing so bad. Engine still ran bad.
-I had read on another forum that a bad distributor would cause the cap to keep going bad so I bought a new one. Replaced it and the cap and the CEL went out on its own and the engine ran like new again. About 200 miles later the CEL came on with a P0422 code again. It stayed on for about 100 miles and went out on its own.
-Now about 3,000 miles later the CEL is on. Code is now P0420 (Catalyst System Efficiency Below Threshold Bank 1) and the P0300. The eng runs great till the temp comes off the peg (100 degrees) then it runs rough and misses till it gets to operating temp and runs like new. This is a new symptom. It ran bad at all temps before. As soon as it started taking info from the sensors. Can’t remember if the term is open or closed loop after it starts.
- So I guess my question is, What are they talking about when they say Bank 1. Is that a side of the eng (Left Bank of Cyl.) or are they talking about one part of the Catalyst system itself.
It is getting old and I am looking at just trading it off and go with something else. I don't want to get rid of it but I can't keep going on like this.
Thanks
-98 Chevy Astro Van. 4.3 Liter Auto. Was a California car before I got it with 163,000 miles two years ago.
-It now has 190,000 Miles.
-Check Engine Light (CEL) came on and eng started to miss at steady highway speeds. Under load eng ran fine.
-Had the code read at a parts house and they came back vacuum leak left bank and bad vacuum left bank.
-After a lot of searching found a bad hose going through the firewall under the A/C. The source for this hose was on the left side of the intake. Replaced this hose with no change to eng performance or check eng light. Checked all the sensors per the Maintenance Manual and all checked good.
-Took it back to parts house and got codes for Coolant Temp. Sensor input voltage low. No vacuum leak showed up. Replaced the Temp Sensor and Temp Sensor wiring for lack of anything better to do. At this point I got a OBDII code reader and the only code was P0300 (Random/Multiple Cyl. Misfire Detected).
-Eng. Performance had gone from bad miss at steady speeds to missing at all speeds and under any load. Changed Spark Plugs and Wires with no change. Changed Distributor Cap and ran like new but CEL stayed on.
-At this point life kind of got in the way and since it was running good it got put on the back burner. After about 5,000 miles it started missing again so I read the codes and all that showed up was the P0300. Replaced the Distributor Cap and it ran like new again. Light was still on.
-Ran fine for about 5-6,000 miles then the miss came back. Life had slowed down so I got into some heavy searching, well I reread the manual for the scanner and realized it was telling me that there was several sensors not working. Found a blown fuse under the hood and found the right 02 Sensor shorted to ground. Replaced that and got a P0422 code (Main Catalyst Efficiency Below Threshold). And of course the P0300. The P0422 did not surprise me since it had been missing so bad. Engine still ran bad.
-I had read on another forum that a bad distributor would cause the cap to keep going bad so I bought a new one. Replaced it and the cap and the CEL went out on its own and the engine ran like new again. About 200 miles later the CEL came on with a P0422 code again. It stayed on for about 100 miles and went out on its own.
-Now about 3,000 miles later the CEL is on. Code is now P0420 (Catalyst System Efficiency Below Threshold Bank 1) and the P0300. The eng runs great till the temp comes off the peg (100 degrees) then it runs rough and misses till it gets to operating temp and runs like new. This is a new symptom. It ran bad at all temps before. As soon as it started taking info from the sensors. Can’t remember if the term is open or closed loop after it starts.
- So I guess my question is, What are they talking about when they say Bank 1. Is that a side of the eng (Left Bank of Cyl.) or are they talking about one part of the Catalyst system itself.
It is getting old and I am looking at just trading it off and go with something else. I don't want to get rid of it but I can't keep going on like this.
Thanks
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