I have had issues with different check engine codes. I have an OBD2 scanner and recently found that I have both a P0171 and P0174 code. These codes are telling me that I am running lean on both banks of the motor. Problem is I don't know what would be causing this problem. I have also noticed that when sitting at a stop light, my engine idles funny. It will drop down to about 400 rpm and then go back up to about 700 or 800 rpm and sometimes bounce back down and then up again. Would this be associated with running lean? If so, what would be causing it to run lean?
2006-12-09 09:25:25 · 10 answers · asked by DangerRanger 1 in Cars & Transportation ➔ Car Makes ➔ Ford
YES IT WOULD. The 4.0L SOHC engines are EXTREMELY sensitive to vacuum leaks. You probably need to replace your rubber intake gaskets. They are not expensive if you buy the entire kit (part # YL2Z-9E473-AA) from the Ford dealer. The kit comes with ALL the rubber gaskets needed plus the timing chain tensioner for bank #2 cassette, which you do not need. The intake manifold is made out of plastic. Check for any vacuum leaks with the engine running at idle. You should definitely hear a "hissing" sound from the somewhere. To isolate the leak, use a bit of propane, or "tune-up cleaner" administer the substance to various potential sources for vacuum leaks. When you hear a reaction from the engine, that is where the leak is located. Repair as necessary. Hope this helps.
2006-12-09 09:35:59 · answer #1 · answered by Anonymous · 1⤊ 1⤋
one cause could be that you have a vaccum leak...which will cause more air to enter the system...but it will also cause the computer to read a lean code then dump more fuel...which in turn will give you a higher than normal idle. It could be your o2 sensor(s). Many vehicles now have 2 or more 02 sensors...but the code should come up as the 02 sensor as well. the other may be your map sensor...but again the code should come up as that. I'd look for a vaccum leak. To do this get some carburator cleaner and spray around the intake...and all of the vaccum hoses...if it stabelizes the idle then you have found your problem. Hope this helps
2016-05-22 23:38:48 · answer #2 · answered by ? 4 · 0⤊ 0⤋
most definately a vacuum leak. check all hoses and lines. the major difference in idle (400-800) is called "hunting" the engine is equiped with an electric solenoid that controls idle. this solenoid is opening and closing looking for its correct idle thats being screwed with because of the leak.
--also if no leak check fuel pressure at the engine. maybe a clogged fuel filter has the engine running lean and the Idle control solenoid is just confused ?
2006-12-09 12:23:52 · answer #3 · answered by smallblock_chevrolet 2 · 0⤊ 0⤋
The hose that goes to the pcv valve is busted, if you look good at the front or near the passenger, right, valve cover the hose ususally leaks there
2006-12-09 10:11:01 · answer #4 · answered by kayef57 5 · 1⤊ 0⤋
mine did same thing, i had; 1.a bad vacum line. 2. the air intake control valve. was bad. the aic is on the throdle body. it took me 3minets to change.
2006-12-09 14:33:32 · answer #5 · answered by waljac6108 5 · 0⤊ 0⤋
replace upper intake gaskets you can ck for other vac leaks but this is usually the problem
2006-12-09 12:35:23 · answer #6 · answered by joe b 1 · 0⤊ 0⤋
Could be a bad MAF... seems to be a TSB on it.
http://autorepair.about.com/cs/generalinfo/l/bl827d.htm
2006-12-11 14:43:22 · answer #7 · answered by MarkH in Tampa 2 · 0⤊ 0⤋
intake o rings thats why condition on both sides
2006-12-10 08:13:52 · answer #8 · answered by Anonymous · 0⤊ 0⤋
clean the MAF and the IAC/throttle body
2006-12-09 09:44:53 · answer #9 · answered by assmouth p 3 · 0⤊ 0⤋
You might also check the O2 sensors
2006-12-09 09:45:00 · answer #10 · answered by blueman2 5 · 0⤊ 3⤋