2003 astro, cargo/work 200100 miles starts right up , idles smooth, takes off great . runs well at lower speeds.
Highway speed thoough , not so much. If on highway, 60-70 mph it is OK, but takes a while to get there. then if an incline it slowly looses speed/power. I can step on the gas and it does downshift, and enging revs, but does not really pick up speed.
recently got an OBD reader, the cheap one Scotty reccomends! Initially it had the mass af code po101, also coolant temp P0128. , and the O2 sensor code P1055. I have been clearing and monitoring. Now , only code that continues is the O2 sensor code. P0155 Ban2 Sensor 1.
Now , I am not a mechanic. I do all the basics oil, brakes, tune ups etc.
So, what I am saying, I am not sure how to go further with the new toy/tool ! LOL When I tried to do an O2 test, while the engine is runing, down at the bottom of the chart , the OBD tool says pass at the bottom of the chart that comes up. But, not sure if it means anything.
would this cause loss of power at higher speeds? Watching my temp gauge, it does not seem to get as high as it used too. Considering replacing the thermostat.
New Air filter recently. cleaned the mass air flow. No misfire codes. ( I have had astros in the past and was used to needing to replace the distributor cap often. )
@d-j-ohio
Not sure about a 2003 model vehicle, but some older cars and I believe most modern cars have the ability to regulate power output if the computer detects the engine is overheating. They also sometimes can switch off the AC (if its on) when this overheating starts to happen. Run the ac when you go on the highway and see if the car switches it off. I doubt a 2003 astro is this advanced, just a thought; so maybe try replacing that thermostat and maybe the 02 sensor, as the readings have a larger effect on performance under highway/high load/high RPM conditions.
@d-j-ohio
no such luxuries on this bad boy
Chack the converter first. Use an infrared thermometer and out reads over 400 degrees f there's y your problem
Also if it is red. You don't even have to bother... It's gone.
200k miles is getting up there. Do a compression test on the engine. You may find that it's just getting tired.
As you discovered, the distributors were a problem area and they would rob the engine of power. Make sure the position is adjusted and the contacts are clean with no soot or cracks on the inside. You can use your tool to check the ignition retard.
The MAF code could just be a symptom of other things. O2 as well.
I would definitely check your catalytic converter. If that thing is disintegrated and plugged up, it will cause all kinds of problems. Hope that helps.
That code is for a high current draw on that O2 Sensor. That sensor should be on the pass side (I think) some where right after the last exhaust post. Do a visual and see if the wire is intact or has come in contact with the manifold or pipe. It would be nice if you could see the output of the O2 sensor.. I use a cheap software that goes on a smart phone and a dongle that plugs into the ODB port. My dongle is cheap( scotty recommends not to use the cheap ones). Mas air flow would cause a big power loss. Check for a loose intake duct after the mass air flow. Just google MASS air for your truck and you can see where it is. Could be a small crack in the intake rubber duct but that should immediately kick a code.
Good luck
@mountainmanjoe,
As I said, I am no mechanic. which is why i am asking here.!! LOL
And , I realize that the codes may just be symptons.
If compression not good, would I not be burning oil,(which I am not) along wiht the low power?
@d-j-ohio
you are right that burning oil is a sign of worn cylinders. But if the valves don't seal then you will see low compression without oil burning. You could also have carbon buildup.
Yes, change the thermostat for code P0128. I would also change the fuel filter. It can cause higher rpm lean condition. I had one that did this years ago. I replaced fuel filter and it ran much better.
I hope this is helpful.
@66 Fairlaine GT, yes , the fuel filter did cross my mind, . But, fuel pump and filter were replace within the last few years. but still will take a look.
@mountainmanjoe on occasion, but just once in a great while, I get valve noise at start up. But it goes away almost immediately.
I make sure to change oil religously, partly because of this.
thanks to all.
@d-j-ohio
replace with a high quality pump (ACDelo, Delphi etc.) I heard many people complain about quality of aftermarket pumps, and having problems soon after replacing.
@66 Fairlaine GT, yes , the fuel filter did cross my mind, . But, fuel pump and filter were replace within the last few years. but still will take a look.
@mountainmanjoe on occasion, but just once in a great while, I get valve noise at start up. But it goes away almost immediately.
I make sure to change oil religously, partly because of this.
thanks to all.