Codes p0507 and p0171

[mizupsi]

Hello, I do hope this is the right place for this.

Anyway, a few months ago my engine began to drop 200-500 RPM at times. Mainly when at idle and when the RPM would drop from something higher (If the engine was revved, it would seem to 'bounce' down a bit.) After a week or so, my CEL came on with p0507. I cleared it and it didn't come on. The rpm problem also seemed to get better at most times. Two days ago, my CEL came on again, this time with p0507 and p0171. The rpm problem is back again too, though a bit worse. Now it gets bad enough to stall the engine for a short time (the rpms would drop enough to make the battery and other lights come on). The rpms usually drop 400-800 rpm, and stay there for about half a second or so. From what I understand, this is caused by a dirty EGR valve, and that I need to clean it.

I opened up my hood today, and after checking around, the intake hose that leads from the filter box down into the (engine, I guess, I'm new to this car stuff ). Also, the cover above the radiator that has the air inlet near the hood opening was disconnected to the little hose that is supposed to be connected to the inlet on the filter box. Could these problems be what has been causing my problems? If so, how?

 

[justanothermp5]

pictures of what your talkin about?
if there was a line coming off of the plastic pipe that connects to the valve cover, then yea that could have caused a vacuum leak which would cause a drop in idle and maybe even stalling

 

[slavrenz]

Hello, I do hope this is the right place for this.

Anyway, a few months ago my engine began to drop 200-500 RPM at times. Mainly when at idle and when the RPM would drop from something higher (If the engine was revved, it would seem to 'bounce' down a bit.) After a week or so, my CEL came on with p0507. I cleared it and it didn't come on. The rpm problem also seemed to get better at most times. Two days ago, my CEL came on again, this time with p0507 and p0171. The rpm problem is back again too, though a bit worse. Now it gets bad enough to stall the engine for a short time (the rpms would drop enough to make the battery and other lights come on). The rpms usually drop 400-800 rpm, and stay there for about half a second or so. From what I understand, this is caused by a dirty EGR valve, and that I need to clean it.

I opened up my hood today, and after checking around, the intake hose that leads from the filter box down into the (engine, I guess, I'm new to this car stuff ). Also, the cover above the radiator that has the air inlet near the hood opening was disconnected to the little hose that is supposed to be connected to the inlet on the filter box. Could these problems be what has been causing my problems? If so, how?

The hose is....cracked?.....missing? You never finish your sentence, and I think you may have an issue with a rotted intake boot.

Neither of those codes has anything to do with your EGR valve being dirty (IIRC), and the front intake plastic piece being disconnected would have no effect on performance.

 

[FORZDA 1]

Hello, I do hope this is the right place for this.

Anyway, a few months ago my engine began to drop 200-500 RPM at times. Mainly when at idle and when the RPM would drop from something higher (If the engine was revved, it would seem to 'bounce' down a bit.) After a week or so, my CEL came on with p0507. I cleared it and it didn't come on. The rpm problem also seemed to get better at most times. Two days ago, my CEL came on again, this time with p0507 and p0171. The rpm problem is back again too, though a bit worse. Now it gets bad enough to stall the engine for a short time (the rpms would drop enough to make the battery and other lights come on). The rpms usually drop 400-800 rpm, and stay there for about half a second or so. From what I understand, this is caused by a dirty EGR valve, and that I need to clean it.

I opened up my hood today, and after checking around, the intake hose that leads from the filter box down into the (engine, I guess, I'm new to this car stuff ). Also, the cover above the radiator that has the air inlet near the hood opening was disconnected to the little hose that is supposed to be connected to the inlet on the filter box. Could these problems be what has been causing my problems? If so, how?

You have an intake air leak after the MAF somewhere....

 

[mizupsi]

The hose is....cracked?.....missing? You never finish your sentence, and I think you may have an issue with a rotted intake boot.

Neither of those codes has anything to do with your EGR valve being dirty (IIRC), and the front intake plastic piece being disconnected would have no effect on performance.

Oh, wow. I'm sorry, I don't know what happened there. Anyway, yes, the tube is cracked after the air filter.

pictures of what your talkin about?
if there was a line coming off of the plastic pipe that connects to the valve cover, then yea that could have caused a vacuum leak which would cause a drop in idle and maybe even stalling

I'll try and get pictures soon of what I'm talking about, thanks.

You have an intake air leak after the MAF somewhere....

Ok, thanks. Where exactly is the MAF located? Is is in the filter box or just after it?

 

[rustychops41]

Definitely check the plastic intake snorkel behind the MAF. These cars are going on 8-9 years old and time & the elements do take thier toll. This causes a lean condition and trips the CEL, and possibly leads shady mechanics to try and sell you a valve job ("Sir, you have burnt valves") and two new o2 sensors ("and your o2 sensors really should be replaced every ______ miles")

 

[justanothermp5]

Ok just fixed a local protege, had missfire problems and had a flashing CEL
he bought new coils and i replaced those, while i was in there i noticed duct tape on the intake after the MAF, took it off and a HUGE crack, so i immediately knew that was what causing it

duct taped it back up (ghetto but worked) until he could get a replacement
CEL went away and his car drives perfect now

 

[mizupsi]

Ok guys, thanks for the help. I've got tie die duct tape over the cracked hose, and the car is running a LOT better now. I have not noticed the RPM problem, and when in gears 1 and 2 and I let off the gas the car doesn't buck and jerk near as much. But there is now another development. I'm getting code p0131 now. I had a little trouble getting the car rolling from a stop (almost like the engine wasn't responding well to the gas pedal) before taping the hose. I can't tell if it is still happening or not, as I get used to new conditions pretty quickly. Anything that might be causing all three codes to be thrown at the same time?

Also, I just realized I've been pretty rude to you guys:

p0171 is "system too lean (bank 1)"
p0507 is "Idle Air Control (IAC) System RPM Higher Than Expected"
p0131 is "Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)"

my apologies.