# Gto problems



## Csallade (Apr 10, 2016)

Hey I'm having a few problems with my gto. I bought the car about a month ago. The guy I bought it from claimed to be an engine builder/tuner but I'm having a few doubts about that. He showed me pictures of the build and the blown block from the engine before this one. The engine was leaking oil, so I tightened the valve cover on the passenger side, fixed a little but not all of the leak. Got underneath the car and all the oil pan bolts were very loose. Anyways, tightened those and no more oil leaks. Then I got on the gas a little bit one day and the next thing I know is I start braking and this clinking is coming from outside the car. I look over and the pulley holder disk thing is rolling next to me. I stop grab that and the bolt then head home. Then I finally get that put back back on. About a week later my car went into limp mode and and these engine codes came up:

P0174 or fuel trim system lean bank 2
P0107 or map sensor circuit low voltage
P0171 or fuel trim system lean bank 1
P0507 or idle too high
P2138 or accelerator pedal position sensor 1-2 correlation error

Emgine mods are:
Ls2
Iron block
Magic stick 3 cam
Texas speed stage 2.5 heads
92 mm throttle body
K&N intake
4k rpm torque converter
Slp ceramic coated headers
Full custom 3" dual exhaust w/ x pipe
Msd ignition

Other problems:
Car idles at 1150 rpms
Surging idle
Gets 8mpg city, seems off for the mods
Difficulty starting
Feels significantly more powerful on different days
Delayed throttle response
Acts like its going to die when putting into park

I have replaced the map sensor. Im starting to wonder if I have bought a lemon and have no idea what route to take. Any advice would be helpful. Possibly thinking its a horrible tune, or vacuum leak. I will post a picture of the engine tomorrow, the vacuum lines may be a little done incorrectly


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## GTO44 (Apr 11, 2016)

Not sure what's wrong but just wanted to point something out. 

If it's an iron block it's not an LS2. It's either an LQ9 or LQ4. Those are the iron block versions and are Gen III based engines, not Gen IV like the LS2. They are actually closer related the LS1 as far as interchangeability. 

Just wanted to point that although that probably doens't help you at all lol


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## Csallade (Apr 10, 2016)

I actually am aware of that. What I was told was that the first aluminum block had a rod go through it. The guy I got it from rebuilt the engine but for some reason decided to go with an iron block. Random parts here and there were used off of the original engine however


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## GTO44 (Apr 11, 2016)

What a bummer situation man. Sounds like the guy that put everything back together either super rushed it or didn't know exactly what he was doing. 

Also the stuff you listed under "Other Problems" sounds mostly tune related. It's probably got a horrible tune or a combination of that and some bad sensors.

Honestly I would find a reputable speed shop that's familiar with late model GM cars and have do a comprehensive check of everything and see what's going on with the tune. 

Probably gonna cost some $$ but if it were me I'd start there.


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## Csallade (Apr 10, 2016)

Ok thanks. In the event that all is just tune related, how much would you say a fair price would be? I've been quoted 500 already and that's not even a dyno tune, just a street


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## GTO44 (Apr 11, 2016)

Csallade said:


> Ok thanks. In the event that all is just tune related, how much would you say a fair price would be? I've been quoted 500 already and that's not even a dyno tune, just a street


Just depends on the place. I was quoted $400 from Real Street in Orlando and $550 from Faster Proms in Tampa. I'm probably going to go with the latter because it's Jeremy Formotto and for me it's worth the extra $$ for his expertise. 

For the quote you got for $500 i would expect it to be on the dyno. I personally wouldn't do a tune if it was street only(for that price). If I'm paying the money I want that bad boy on a dyno lol. Now it could be more expensive if they are doing Dyno AND street tune. But I don't think I'd spend $500 on street tune alone. Plenty of shops out there that can offer the dyno tune for around that price...

Also look around even if its a shop that's not that close to you. I'm gonna have to drive 2 and a half hours to get mine dyno tuned (after i install my headers/mids/hpipe). I will pass 50 shops on the way that offer dyno tuning lol But the place I'm going to is very reputable and come highly recommended from the LS community. Especially in your situation where they are going to be tracking down problems and not just putting a simple tune on it... You want someone that has experience with these type of cars.

Just my 2cents


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## Csallade (Apr 10, 2016)

Ok haha thanks for all your help. I will hopefully get it tuned here pretty soon but I have a sneaking suspicion that there are a few more problems probably with sensors and whatnot.


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## XR3 (Jul 10, 2016)

I'm having similar issues and have a bad accelerator positioning sensor. GM outsourced it's production and guess what they are no longer made. I bought a pricey Lokar/Williams control aftermarket off Ebay and it's non responsive. Turns out they only support programming for 06 and I have an 05. Funny thing is the part will only come up when I put in the proper GM part number 92189341. I'm on the second sensor and this thing only has 9000 miles on it!


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