prof15
08-23-2009, 12:58 PM
I apologize in advance for large post but I want to explain every thing to see if I can get help to figure it out what seems to be causing the problem I am having.
Lately I have been having Idleling problem, the car drive normally and when ever I get to a stop sign or light the rpm drops below normal and goes up and down but it never reach the normal rmp. I have been doing some maintance to my car and lately have replace a few things. Here is a little history line as when the problem started.
1 ~month ago I did the nonfouler trick-but the light came back about 50miles after I reset the computer.(The weird thing is that during this period the car idle was bad but it returned to normal once the cel light came back on).
2 About a week later I drove through big puddle of water during a big storm. The car seem normal.
3-About a 2 weeks after that I was going to do a long trip so I decided to check every thing on the car. Replaced: Air filter (it was really dirty).
(The day of the trip I filled the tank and pored a bottle of fuel injector cleaner)
4- A week later in my way back from the trip, when I was about 20 miles from home the cel went from solid to flashing and the car started to act weird. (Next day I went to autozone and got it scanned, got a random misfire code) Replaced: spark plugs and cables The problem stayed the same.
5- After replacing the Spark plugs and cables, the cel came back to solid since I still need to replace the O2 censor. But the car still had the bad idle, so I checked all the lines vacuum lines and replaced the check valve, tried cleaning the egr but couldn't remove the small screws that hold it to the solenoid, and also cleaned the MAF sensor. The proble stayed the same. (I found that most of the lines were covered in oil so I cleaned them, but did not find any leaks broken hose or leaks under the car.)
6- About two week I took it to a mechanic and the scanner did not retrieved the random misfire code. Later that week went back since the car started to die when I came to an stop sign or light and even though the light was not flashing he got the misfire code and he told me that I needed new coils.
7- Early this week I changed the oil, and replaced the rear left brake caliper since it started to leak and also replaced the ignition coils and the problem still the same, new coils seem to have help a little since the car doesn't turn off at lights and the idle some times stay at normal but still goes below at most of times.
Today I went by autozone again, and got it scanned and I got a new code (P0171)
Lean Air/Fuel ratio bank 1
Probable cause
1- Low fuel pressure
2-Large Vacuum leak
3-Dirty /Defective MAF Sensor
4-Engine Mechanical Condition
Do you guys have any suggestion or have had a similar experience before? I will probably check again for a vacuum leak and clean the MAF sensor again.
But at this point I might have to take it to the mechanic since I don't want to keep buying parts or replacing things to have the same out come.
Lately I have been having Idleling problem, the car drive normally and when ever I get to a stop sign or light the rpm drops below normal and goes up and down but it never reach the normal rmp. I have been doing some maintance to my car and lately have replace a few things. Here is a little history line as when the problem started.
1 ~month ago I did the nonfouler trick-but the light came back about 50miles after I reset the computer.(The weird thing is that during this period the car idle was bad but it returned to normal once the cel light came back on).
2 About a week later I drove through big puddle of water during a big storm. The car seem normal.
3-About a 2 weeks after that I was going to do a long trip so I decided to check every thing on the car. Replaced: Air filter (it was really dirty).
(The day of the trip I filled the tank and pored a bottle of fuel injector cleaner)
4- A week later in my way back from the trip, when I was about 20 miles from home the cel went from solid to flashing and the car started to act weird. (Next day I went to autozone and got it scanned, got a random misfire code) Replaced: spark plugs and cables The problem stayed the same.
5- After replacing the Spark plugs and cables, the cel came back to solid since I still need to replace the O2 censor. But the car still had the bad idle, so I checked all the lines vacuum lines and replaced the check valve, tried cleaning the egr but couldn't remove the small screws that hold it to the solenoid, and also cleaned the MAF sensor. The proble stayed the same. (I found that most of the lines were covered in oil so I cleaned them, but did not find any leaks broken hose or leaks under the car.)
6- About two week I took it to a mechanic and the scanner did not retrieved the random misfire code. Later that week went back since the car started to die when I came to an stop sign or light and even though the light was not flashing he got the misfire code and he told me that I needed new coils.
7- Early this week I changed the oil, and replaced the rear left brake caliper since it started to leak and also replaced the ignition coils and the problem still the same, new coils seem to have help a little since the car doesn't turn off at lights and the idle some times stay at normal but still goes below at most of times.
Today I went by autozone again, and got it scanned and I got a new code (P0171)
Lean Air/Fuel ratio bank 1
Probable cause
1- Low fuel pressure
2-Large Vacuum leak
3-Dirty /Defective MAF Sensor
4-Engine Mechanical Condition
Do you guys have any suggestion or have had a similar experience before? I will probably check again for a vacuum leak and clean the MAF sensor again.
But at this point I might have to take it to the mechanic since I don't want to keep buying parts or replacing things to have the same out come.