2002 gmc sierra 1500 5.3 v8 p0507

DTC P0507 Idle Speed High.... EASY DIYer ideas start with Throttle Body - might want to spray it with cleaner...check for vacuum leak- any leak after throttle body - and vac lines ie PCV, ust the old tried true spray trick to look for a vacuum leak... there is no K&N filter? aftermarket anything?

So this is a follow up on my post. I have a few aftermarket parts. Its lifted 6inches. Flowmaster cat back exhaust. Airraid airfilter installed from the factory. Throttle body spacer. and i just upgraded the MAF to a JET Performance one. After buying a new MAF sensor, IAC Valve, went to swap out the EGR valve but found out there is none. Took apart and cleaned the throttle body. I have done the old spray test with carb cleaner around the intake manifold and found no leaks. I still have this code appearing. I installed the MAF Sensor 60 miles ago, replaced it, and the light came back on on my way home from work. Im running out of ideas as to what could be causing this. I guess ill change all the vacuum lines and reset the code. Discover more Ram Trucks Toyota Camry Hybrid Truck When i replaced the MAF sensor, i have fixed the really rough idle it was previously experiencing: idling from 900rpm all the way up to 1500rpm, then back down to 900, in repeat until i put the truck in gear. Replacing the maf fixed this. Any ideas as to why p0507 code would still be appearing? FYI: I have to put radiator fluid in the truck every so often, but have not found a leak in the hoses or radiator but still find im leaking fluid. Hope all this info can further diagnose this problem i appreciate any posts related to helping me solve this matter. Thank you.

I show an EGR for a 2002 GM 5.3L ? @ by the oil fill cap - tubes comming out of exhaust manifold? What is the truck idle speed? My 2cents- All those modifications are likely the issue.

There is a slot for it on the heat shield of the exhaust manifold, but on the actual exhaust manifold there is nothing there. I could upload a picture but from the research I have done and people I talked to, some have it, some don't. 2002 was the last year they used a EGR valve from what I understand. the trucks idle speed as of this morning was 700-800rpm. Which is a lot better than the previous 1000-1500 fluctuating idle rpm before installing a new maf sensor. Here is a picture of my passenger side exhaust manifold http://i1258.photobucket.com/albums/ii5 ... 44fbd.jpeg Problems I had before the new MAF were: Very rough inconsistent idle speed. Down shifts were extremely hard on the tranny during braking because it almost seemed like there was a air leak. (if you drove with two feet, and you were braking while still giving it a little gas, that was what was happening every time I braked) the trucks constant changing of idle speed while in drive sitting at a stop light. The truck would literally get up to 25mph+ without me even touching the accelerator once I put it in drive. All these were fixed with the installation on the new MAF. I reset the code and 50-60 miles later it came back on. Might replace the throttle body here soon if I cant get to the bottom of this. All the upgrades were done by the GM Dealership as per the part of the deal of me purchasing the truck. Lift, Throttle body spacer, cat back flowmaster exhaust. I had a shop retune the ecm when the truck was brand new as well. I have not had a problem up until about 180k miles. There is 191k miles on. The Service engine light displayed after I had hit a sign. Only sustaining cosmetic damage with a dent on the right front quarter panel. How could the upgrades be causing a problem? I still have all the stock parts in storage aside from the suspension and exhaust.

Very interesting on the EGR especially for a California emissions vehicle..Live and learn/ THe new MAF has solved the DTC issue- OR is there still a code- and what code? Those modifications - PCM retune - no idea what they did- everything from ECT to o2 sensor voltages are comapred to a stored norm anything different will set a code- The BEST quality parts are at your GM dealer- Strongly suggest you get a scanner live data and bi directional if modifications are important to you,

kev2 wrote: Very interesting on the EGR especially for a California emissions vehicle..Live and learn/ THe new MAF has solved the DTC issue- OR is there still a code- and what code? Those modifications - PCM retune - no idea what they did- everything from ECT to o2 sensor voltages are comapred to a stored norm anything different will set a code- The BEST quality parts are at your GM dealer- Strongly suggest you get a scanner live data and bi directional if modifications are important to you, 1.Truck was bought in California late novemember 2001 if I remember correctly, but has lived its entire life in Reno, Nv 2.After installing the new MAF sensor I reset the DTC, it came back up with the same code, p0507 after 50 or so miles were clocked in. 3.PCM retune was for larger diameter tire adjustment, transmission shift firmness, removal of rpm/speed limiter, tune for high altitude if I remember correctly and just a few minor things. Nothing to extreme like fuel remapping or anything like that, as the shop did not have a dyno. 4.Are you referring to the Delphi brand sold by GMC? 5.Not a heavy modifier, just the basics to get a little more power and increase fuel economy, ie: air intake, exhaust system. I am re cleaning the throttle body today, once it cools off, will reset the dtc, and drive around tomorrow and see if it comes back up. This is what I have done so far to try to eliminate the p0507 I first encountered last year: Throttle body clean, IAC Valve replacement, MAF sensor replacement, air filter clean, air intake tubing clean, and overall light inspection of intake system without removing intake manifold, also spark plug replacement. Would appreciate any suggestions, maybe something I have over looked, to clear the p0507 engine code. Thanks fot your input Kev2

The trouble tree for the p0507 starts as I posted - with scanner can you adjust the RPM- basically the step is to determine if PCM is driving the IAC OR something else is contributing to idle discrepancy... Things that I want to mention - Being SOLD in calif it may have calif emissions system - different. Again a scanner is critical these days- Start and Idle issue- I would want to check ECT where does it start and does it reach @200degF ? Look at fuel trims - maybe a hint as to the start idle issue Also the o2 sensor readings- so integrated a system gotta look at EVERYTHIGN Don't wast money on a K&N and use AC Delso plugs... PS - Trying to add DIYer tests WITHOUT a scanner.. have you tried the spray trick to isolate a vacuum leak? Have you done a fuel pressure LEAK down test?

is this drive by wire?variable valve timing does not use egr in conjunction with drive by wire.if this truck has drive by wire and uses a electronic throttle body and no throttle cable then either a vacuum leak.....i use to use propane....carb clean i have seen catch fire propane is safer.a bad pcv or a dirty throttle body.to clean the throttle body on drive by wire make sure ignition switch in off position and I disconnect the wiring connector at the throttle body.dont use tools just rags and carb cleaner.

All I have is a simple code scanner. So im not able to perform those tests with what I have. I have tried the spray trick to try and find a vacuum leak and it checked out with no vacuum leaks. I used throttle body cleaner. I have not done a fuel pressure leak down test. This is a drive by cable. Meaning it actually has a throttle cable and is not electronic.

Check for sticking throttle linkage. Check the idle stop screw that is holding the throttle open TPS voltage will be high. If it has been adjusted out too far, this is the cause of the code. Vacuum leaks that are a frequent cause of this code.This code is set when the idle speed is over 200 RPM above the desired idle speed for 5 seconds.